I have to say this first: The Frontier is a Big Kid seat. I would recommend the Marathon over the Frontier for someone with younger/smaller children. The MARATHON has rear facing capability (which is required for kids younger than 1 AND less than 20 lbs, it is also best for children to RF as long as possible), its less upright (which is good for dozing off), and it is higher up (which allows smaller kids to see out the windows), it harnesses to 65 lbs, and my "will be six in six weeks" son is in no danger of outgrowing it, and of course it has way better fabric options (LOL). I'll say again that I would NOT put a child that was any younger than TWO (or even three!) in the Frontier- I just can't see them being at all comfortable in it. In other words...Do Not buy the Frontier as a replacement for your infant carrier... if that describes you, look at a different seat!!
I have two sons, a 43" 41 lb almost 6 old, and a 39" 36 lb 3.5 year old. Both are similarly sized in the torso, and currently sit an inch or so below the top slot on our Britax Marathon. Both are perfectly happy comfort wise in the Marathon, but that's the problem, because we only have one Marathon (so of course it's the most popular seat in the house- the kids don't understand switching seats). Our other seat is perfectly fine, but it only goes to 40 lbs.
SO, we now have a Marathon and a Frontier in a Honda Accord.
Harness, crotch strap- the harness is incredibly easy to adjust and can go to an almost exact height instead of being an inch or two higher every time you adjust it and there is no rethreading. You can push it up more while the seat is installed in your car, but you can not move it down that way, you have to pull the seat out to adjust down. The crotch strap has three positions, and the second was almost exactly even if not under both my boys. The manual says use the closest one that is not under your kids, so we chose the third position out which is actually quite a bit further out.
Comfort- Both kids love the seat so far and say it is comfortable, however, they have only been in it twice each, and no one has fallen asleep in it yet so I can't say how that would be.
Cup holders- I agree that they are kinda weird and look like the part for the cup is too small to be useful, but my sons have already had two or three different random cups of ours stored in it, so it must be functional enough.
Weight - After reading the reviews online I was expecting this seat to be a 2000 lb elephant when I went to see it in the store. I didn't think it was all that heavy, I lifted it off the high shelf at BRU all by myself. I really didn't think it was any heavier than the marathon, but who really cares anyway? I don't plan to carry the thing around on my back or anything, I plan to attach it to- and leave it in- my car. I also don't see how you pick up a seat built sturdy enough to harness an 80 lb kid and expect it to be light.
Size- as I said I was expecting an elephant after reading the reviews but was surprised to see it was comparable in size in the store when set side by side with the marathon. But in my CAR, however, it looks quite a bit larger, and is deep enough of a seat that it sticks out over the edge of the backseat by an inch or so. (Honda Accord) We had to move the passenger seat up a tad so my son's feet could fit between his seat and the front seat.
Install- It is always a very good idea to READ THE MANUAL prior to purchasing a seat to be sure your car is compatible with whatever seat you are thinking about. (you can read it online- which is also a good idea because it is very difficult to read a manual that is tethered in the seat part of a brand new seat while your kids are all excited and jumping in and out of it). This seat has three methods of install described in the book for harness mode. LATCH, and the long/short belt paths for the seatbelts. (note you cannot use LATCH for any seat after your child reaches the weight capacity your car manufacturer says is the limit on your LATCHes. Most cars are limited at 40 lbs, but some go to 48)
LATCH looked simple enough if you READ THE MANUAL because the LATCHes come out of the back of the seat and you can pull them tight through the seat which looks to me like it would give you a better angle at tightening them, especially if the seat is in your car directly next to another seat. But, My car's LATCH limit is 40 lbs, and my almost six year old is 41 lbs, so LATCH is out for us.
Which leaves, Seatbelt install. I have never thought it was easy to seatbelt any carseat into the car, just because of the nature of getting the seatbelts to lock properly and pulling them as tight as I would like. The MANUAL gives us two options for seatbelt installation with a shoulder belt, long and short belt path (lap belt only was only compatible with short belt path). The manual describes and shows pictures of what type of seatbelt placement is usually best with which belt path.
Short Belt Path- looked compatible with my car from the pictures so we started with that. Easy, right, just follow the LATCH path with the belt, kneel and tighten... or not so easy. The trouble is - for those of you that are wondering- that the belt stalk and the seatbelt connection part have to be SHORT or line up exactly with the hole in the back of the seat, and the head of the belt stalk has to fit into the hole in the seat at the correct angle for you to be able to tighten the belt properly. (but no risk of another child unbuckling your car seat by pushing the button, since the button would be inside the back of the car seat) We attempted (and failed) to line it up and tighten it several times. And honestly it probably was tight enough that there wasn't "more than an inch" of wiggle, but I like my seats in REALLY TIGHT, so...
Long belt path- the trick to this one is having a second person hold on to the belt and keep it from retracting while you are threading it through the holes. (you will need both hands for this.) You need ALL of the belt and if it comes all the way out and starts retracting (and locking), you have to take it out of the seat and start over. Once we figured this out, the installation wasn't so bad, but I have to warn you that the seatbelt in my car (passenger rear) was only about an inch longer than what we needed on this belt path. After that you put your knee in the seat (or sit in it) and you can tighten it.
Was it hard to install? No harder than any other seat I've installed with seatbelts, and it had two belt path options, well maybe a little harder since all the threading for the long belt path. Next time I'm sure we will get it in the car in the usual 5-10 mins. Since we know which method works in my car. Will I be moving it anytime soon? No, but do I usually take any of the seats out unless I have to? No.
Edit to add that yesterday the seatbelt came randomly undone (July 14, 2009). Fortunately I check the seats every time we get in the car (Yikes- a 25 lb projectile with a 42 lb 6 year old attached to it). Anyway, as I was alone and with both of my children, I tried the short belt path again, and I was able to get the seat in quite securely that way. This time I threaded the belt through, latched it, and then moved the seat so I could pull the belt stalk/buckle through the whole in the back of the seat so it lined up properly, then intallation was a snap, and even my husband couldn't get it tighter when we made it home. I'm more comfortable thinking something won't brush the seatbelt button with the beltbuckle inside of the seat.
Also, we have now fallen asleep in the seat and have NOT had head flopping issues.Get more detail about
Britax Frontier Booster Car Seat Rushmore.
