The crotch strap.
This seat looked ideal in every way. I liked it right out of the box, and when I put it together. It was exactly what I was looking for.
Then, I sat our average-sized 3 1/2 year old in it, boxed it up and sent it back, very disappointed.
The crotch strap, in the closest position, was beneath the back of my son's crotch. In the farther (and only other) position, it was even with, and slightly pressing against, the front of my son's crotch. In other words, no room to grow whatsoever. There is no way possible that this seat would allow my son to sit comfortably in a five-point harness all the way up to 65 pounds. At that point, the strap would be well beneath his crotch and be uncomfortable and dangerous. No way... and I really wanted it to. If there was one additional slot for the strap, an inch or so farther out, this seat would be PERFECT, in my opinion.
So, I gave this seat a 3 out of 5. For a younger child, or one just reaching my son's age and size (again, he is very average in weight, height), I would probably rate this seat a 5. But, since it clearly will not be able to do what it says it should do, up to 65 pounds, I cannot give it a 5. I honestly don't know how any child can be accomodated in this seat up to 65 pounds, unless they are a very, very skinny 65 pounds.
If Graco updates this seat to add one extra slot an inch or so farther out for the strap, I would buy it again immediately. I was, and am, a little angry that the seat won't work as advertised. Buyer beware; look up the few other comments on the crotch strap first. Then, please, go to the store and "test seat" this seat before buying, and please consider how big your child will be at 3 1/2, or older. Otherwise, you may find the same disapointing fact I did.