I've had a 2.OT Genesis Coupe since March of 2010 and while not a 3.8 I can attest to the quality of the ride and manufacture.
We haven't had any single issues (knock on wood) and have been really happy with it. I spoke to another owner on Friday night after my baseball game and he has not had any issues whatsoever with his either and is just as pleased.
The quality is there, so I'd just suggest going for more drives to really nail down if the performance is there for you or not.
'08 RL/Black/Tan Top-5 SPD/Monsoon/Kenwood DNX6960/GMMP+Trifecta Tune/Dejon CAI/Solo Mach Shorty w/Quad Tips/Dark Tint/'SKY' Illum. WR & Door Sills/RK Sport Rear Spoiler/Painted Rear Fascia/Opel GT Antenna/Pntd Calipers/HID/DDM + JPM console