IMO the unlimited products glass isn't as good as the harwood or cervinis (neither of these companies make stuff for your car) but it is on par with pretty much everyone elses glass parts. If you are looking for factory fit and finish stick with the stock stuff. I have used unlimited products glass on a few camaros and they worked. Fiberglass part quality can vary greatly even on identical pieces from the same manufacturer. I expect to have to rework (to some extent) most glass parts to get them to fit properly.
I recently painted this Camaro for a friend. He claims this frontend is from unlimited products (on the car when he bought it). Hood is a harwood that I cut to fit. The entire front clip required a lot of work to get a decent fit but in the end I think it is acceptable.