We got Saoirse a new car seat for the van to see if she just hates car seats in general or if it's just her bucket seat (which she still fits in quite well). Well, turns out she hates car seats, but she hates her bucket (a Chicco Keyfit 30) more. Which is understandable as it is far less padded than the new S1 we got her, after I did much research. Overall, I am happy with the new purchase.
I'm going to break this down into pros and cons.
Pros: very well padded, looks comfy, the only valid 3-in-1 convertible seat, pretty easy to install if you follow the manual, the cup holder seems like it would actually be validly usable for a child if they have, ya know, arms long enough to need a cup holder. Goes rear facing to 40 lbs. Harness forward facing to 70 lbs. High back booster til 100 lbs. No rethread harness and head rest moves with one hand (which adjusts the harness as well.) Very nice air head pads. 2 cup holders. Steel reinforced.
Cons: it is big. Rear facing it takes up a lot of room back to front, so it wouldn't really be valid in smaller vehicles (we have a Dodge Grand Caravan). Wouldn't play well with other car seats as it is broad, but we have Captain's seats so that wasn't a concern for me. Joseph doesn't much care for the harness straps, but they don't bother me so that is a matter of opinion.
It's pretty heavy, about 25 lbs, which is both a pro and a con. Under new regulations, LATCH shouldn't be used past when the child's weight + the car seat weight= 65 lbs. This seat rear faces to 40 lbs, so I shouldn't have to switch to using a seat belt til Saoirse is forward facing (which I don't plan to do until Saoirse is 40 lbs and is therefore too heavy to rear face in this seat).
As you can see in the above picture, I had to add a rolled up towel to get the appropriate recline on the seat, as the Grand Caravan has bizarrely slanted seats. This is allowed, per the manual.
Disclaimer: I was not paid or reimbursed for this post. I bought the car seat myself, all $229+tax. The opinions expressed are mine alone.