Lots of experience here. I own an aftermarket set.
The aftermarket sets are a little bit of a pain to put on with the straps that must go under the center roll bar if you have a factory shelf for speakers.
They look really, really cool though!
Now what I do not like about them is the fact that they can mar the rubberized trim around the clamshell (my set anyway).
I also have been caught in the rain and had to scramble to get them off the car and into the rear trunk so they fit (which they do, but only after trying them a few different ways). Then getting the top up while it poured wasn't any fun.
Lessons learned: buy original ones if you can find them. They're worth the extra money, easier to put on and take off, and probably much better made.