Fitment will never be perfect on aftermarket parts. I've seen $30k Hamann kits with poor fits, too. The best you can do is work with a bodyshop to make it work.
On my particular car, the driver's side fit really well but the passenger side bowed out just a tad (near the marker light). Good from 4 ft away, but not as tight as the factory. Fiberglass doesn't bend, so I'll live with the bow. I could have gone with a polyurethane bumper, but they were more expensive and i heard they bow after time. Hopefully, the fiberglass will be solid (only time will tell). I'm not sure anyone would notice unless I pointed it out, but I was staring at all the seams. The front hood gap looks great, though, which is most important.
I still haven't picked up my car from the install, but after I do I'll post pics.
The important thing to know is that on some cars, the bumper will mount right up. On others, it will take some minor tweaks on the bumper. One thing is for sure... for the money, this makes the car look amazing.