While I can appreciate what you're saying, if he's not 35lbs by now, he probably will be within the month. The last accurate weight we got was 2 1/2 months ago, and he tends to average about 1lbs/month. Based on the measurements I found on this site, the Cosco you recommend has the same height for the top harness, so we'd be in the same boat we are now.
I guess a better question is what high-weight harness do you all prefer? The research I did had me really liking the
Radian seats (yeah, I know, the more expensive seats, I have expensive tastes). I like the smaller footprint, the folding ability, the longer lifespan. If the roominess is true, that is a big plus as well. However, just because it's more expensive doesn't mean it's better.
I know there are lots of
Britax owners out there, but I had never even heard of
Sunshine Kids and
Radian seats until I started this research. I know of one owner who has been very happy with hers, but only one owner. I was hoping to get a bigger sampling of opinions on various seats here.
Thanks again for your input so far.