Aftermarket weatherstrip kits range from really crappy to somewhat above average in quality and durability.
There is only one source for really good weathership and that's GM.
The problem is the GM stuff, which is, obviously, made to OE specs and has the durability one expects from new car weathership, is much more expensive.
Consumers concerned more with price than with quality have forced the aftermarket to just about universally go to cheaper materials.
This is not to say that aftermarket weatherstrip won't work. The better aftermarket weatherstrip is ok, it just one last near as look as the more expensive OE stuff and in some cases doesn't seal as well.
I'm looking at redoing the weatherstrip in my 15-year old C4 and I'm going to bite the bullet and buy it from GM.
If I had to go aftermarket because I simply could not pay for the good stuff, I'd buy an aftermarket kit from Zip Products.