I got a chance to listen to it briefly and at very low volume. Even at low volume, I can felt the low end extension (bass/midbass) which make me felt like I am inside a studio. I can't localize where the bass is coming from, it seem like it surround the entire cabin of the car. To me, it felt good.
I think it got 3 10" woofers. Bose is known for good midrange and high, but lack midbass. I think they correct that by having 3 10" woofers for clearer deep frequencies and sound pressure.
I think it should be good (maybe really good).
I'm keeping my finger cross because to me sound quality in the car is very important especially when you stuck in traffic.
I figure a few people must have been able to listen to it in person. Was it improved over previous G models? I'm disappointed in the Bose system I have in my '05 G35, so I'm hoping whatever the Q50 has, it's much better than my current one.