Guys both the 350z and the 335i coupe are great cars. Both post the same 0-60mp/h. Aussie magazines have them at 5.7 seconds. So stop arguing they are just as quick as each other. Some days the z might be faster, sometimes the 335i, just depends on lots of things, so put your testosterone away and be good boys.
As for quality, please BMW guys don't go there, cause BMW in Australia only offers a 2 year warranty, compared to other manufacturers that offer much better warranty. You could interpret this as lack of confidence in their product holding up to long term use. Of course, then again a long warranty means nothing if the driver is abusive on the car.
So there you go, both are quick and both are good cars.