Heck no. I've been using one all season and I love it. If made properly it will have the same weight transfer characteristics as a fiberglass, just more durability and less weight. I'm more about the durability since I have to add 100+ of weight...no cracks, even when wheel hopped.
Are the select style CF seats identical to the actual select?
I'd hate to spend $200 on a seat and it not fit. The large select is tight, but fits nicely. Any smaller and it won't work.