idk.. they're only about 200 llbs more than the GTI which stand at 3000lbs already
are you positive it wasn't a 4 cylinder?
My old man bought a 2010 3.8L V6 Genesis Coupe a few months before I bought my 2010 GTI. Stock vs stock his had a little more "umph" 0-15mph and 85mph+. Stock GTI felt like it has more torque and power btw 15-85, then it slightly fell behind. I now have stage 1 with intake, and while his still has a slight edge being RWD immediately at launch, I have significantly more available torque and "go" from 10mph all the way up past 120 and beyond.
The genesis coupe is pretty nice. It felt a little less responsive and nimble than the GTI, but I really enjoyed the rumble it's V6 engine let out (also liked the fact that it can run on regular unleaded). The GTI feels more polished, is nimble, gets better mileage, and feels more "mature". You can also put something that isn't a midget in the back seat.
Both are nice cars.