I bought this carseat as a replacement for the Graco Snugride that my son outgrew at 4 months. He always liked his Marathon, but now that he's over 1 year and facing forward, he's really happy - this seat allows him to sit high enough to see outside the car. It must be very comfortable too, because he regularly falls asleep on long trips.

The installation is easy and very secure. Just connect the LATCH connectors, put your knee in the seat, and pull the straps to tighten. Connect the tether to the tether point that most newer cars now have, tighten that strap, and you're done. The only down side - this seat is built for kids up to 65 lbs, so it's VERY large. It probably won't fit in some smaller cars, but I was able to install it in my CR-V and in a RAV4 (both centered) with no problem at all. Both of these small SUVs still have room for 2 smaller adults in the back seat with the Marathon installed.

A couple of tips for airline travel - the seat is approved for airline use, but the LATCH connectors won't work. If you install the seat using the airline seatbelts and tighten the belt properly, you won't be able to operate the latch to free the seat when you arrive at your destination (I learned this the hard way!). To make life easier, ask for a seatbelt extender when you board the aircraft. Use the extender to connect the two halves of the seatbelt through the back of the seat. Then you can tighten the belt to properly secure the seat and still release it easily when it's time to disembark.

Second tip - this seat is a backbreaker if you have to carry it through an airport to make a connection. Instead of carrying it, get a luggage cart and attach the seat with a bungee cord. Now, put the kid in the seat, strap him in, and leave the stroller at home.

Oh, and get the seat at Traveling Tikes - about $40 cheaper.

This is a good car seat, albeit with some observations.

Older children may not fit into the Marathon, as the base is too tall and they're likely to outgrow it in height way before they reach the 65 lb weight limit. The Roundabout has a lower weight limit (to 40 lbs) but it may indeed be a better choice if you're transitioning from an infant seat because of possible design flaws in the Marathon.

The Marathon seat is shallow and the crotch strap is too short, especially for toddler boys. The Marathon measures 6 inches from the back of the seat to the base of the strap. The Roundabout is deeper, 7 inches from seat back to the base of the strap, which is perplexing. Why would Britax make the larger seat shallower, if it has to fit both infants and older children?

Second, the quick release of the Marathon is so easy to use (gently lift the metal part under the front flap) even a toddler can do it- if they fiddle with it they can loosen the harness while strapped in! Teaching the child the meaning of "no" and placing safety pins on the flap are possible solutions but not what one would expect on an expensive car seat.

Please note that some models of the Marathon have a flap with velcro that's easy to lift. The Marathon Greystone sold by Target has a slightly different flap (the metal clasp is still underneath but hidden by a flap that's sewn on the sides - not velcroed like the picture). This looks like an improvement, as most Marathon models have the velcro version. I don't know if the amazon model has this new flap.

The Roundabout has a different harness release system (button) and you need to press hard to release it which makes it more child proof.

Lastly, the Marathon and the Roundabout are handwash & drip dry only according to the owner's manual and care instructions attached to the seat.

It's a good seat for young toddlers, not so much for older ones, especially boys.

I have two of these seats and I love them. The latch system is incredibly easy to use and my son is very comfortable in the seat. I've had the seats for two years now. On two instances my son (at 26 months) reached down and opened the velcro cover over the strap release and has actually released the straps all the way while in the car... And, YES, each time he has been strapped in CORRECTLY (tight with no slack and only able to fit two fingers under the strap). There were a few other instances that week when he tried to do this again but we were able to stop him. Since that week, about six months ago, he now knows it's not safe to touch that part of the seat and he hasn't even tried to loosen it again. Even in spite of this, I love the seats and plan on using them until he outgrows them. I just want to let people know that even strapped in 100% PROPERLY, there is still the chance that your child can reach the strap release. No one can predict all the possible outcomes of the curiosity of a two-year-old. Don't keep blinders on...just because they aren't SUPPOSED to be able to, DOESN'T MEAN IT CAN'T HAPPEN. (This can be said about any product).

We agonized over the decision to purchase this car seat as the price tag was hefty and really really stretched our budget. Let me just say that after owning it for a few days, I am more than pleased with the purchase. If you are on the fence with this car seat, like we were, I say "go for it" you won't have any regrets.

We purchased two of these seats. Once for our infant son (for when he outgrows our stroller/car seat combo), and one for my 30 month old son. My son previously had the Eddie Bauer 3-1, which at the time seemed like a good purchase. We needed an extra seat for the inlaws, so we "upgraded" to the Britax. Even my husband noticed that we get what we paid for. The Britax fits much more solid in the car (even though we used latch with the Eddie Bauer, it wasn't as secure)...it also is significantly more comfortable for our son. The seat sits higher, which makes the ride more enjoyable, and there is a lot of cushion in the seat. The straps seem more secure and are much easier to adjust based on your child's clothing. Another plus, is that it seems a little narrower (although still very roomy), so the backseat of our Passat Wagon is less crowded than with the Eddie Bauer. I also appreciate that the cover is removable and washable...may car seats are spot clean only, which isn't great when you have a toddler.

The biggest point that sold us on the seat, was that after your child hits the 40 pound mark, most seats can no longer be used as a 5-point harness system...this seat is an exception and lasts until 65 pounds. In the end, we are hoping this is the safest way to go.

So, hopefully this review will help you with your decision...everything for baby seems so expensive, but this is one purchase you won't regret.

I had some issues with this seat when it was rear-facing. It needed a locking clip, which Britax does not provide, to keep the seat stable because the lock-offs popped open. However, it's completely different forward-facing. I can actually install this seat without any problems. Initially, I had taken it to the police dept and the officer installed it for us. Then a couple of months later, my son's diaper leaked horribly all over the seat, so I had to take it out of the car to clean the cover. I was nervous about re-installing the seat, since I only trusted the police dept to do it, but the directions were extremely clear and after my installation, the seat is rock solid.

My son loves riding in the Marathon. He's so comfortable in it and doesn't complain, even during long trips. I highly trust Britax and I believe that this seat is worth every penny.

This car seat sounds pricy at first. In reality, it is'nt. It is designed to hold a kid upto 80 lbs with 5-point harness. No other car seat offers this kind of design and reliability. Upholstery and the ruggedness speaks for itself. This car seat will save you money because you don't have to buy a booster. It is worth your kid's safety to be in a 5-point harness system for as long as you can. I tried this product at Babies-R-Us before buying it. I made sure I knew how to install it and how to change the strap position. With a little bit of practice, a trained monkey can do it.

I strongly recommend this car seat if you are a picky nervous-wreck parent like me. Nothing wrong with that. Check various stores in your neighborhood. I found a good deal at Target. Some stores have a close-out sale. Saves you atleast 50.00 bucks !

I have rated this product 4 stars because the straps tend to twist but it is not a big deal once you get used to it. I am using it in a 2001 Toyota Sienna and it looks comfortable for my 18 month old daughter.

I strongly recommend this car seat if you want your kid in a 5-point harness for as long as you can. No other car seat is close to comparison.

We ordered it as soon as the baby was born. But used a hand me down Snug Ride infant car seat for the first few months.

After that the Marathon has stayed with him for all his travels on cars and planes.

This fits on a plane seat in Economy Class (ask for a lap belt to tether this to the seat). Most airline clerks will insist on checking it in since they are unaware that you are allowed to take it on board and fit it on the seat. So we always used to take out a print out from airline web page and FAA that says that car seats are recommended on board.

We have done transcontinental trips. We could not have done without a car seat, which allowed him to sleep as peacefully as he would on a car ride.