I would disagree insofar as my experience with my 350z (which is a 2006). The thing has been stone cold reliable and the fit/finish is just fine. There was some talk about oil consumption problems with that year motor, but most were replaced under warranty.
Infinity versions of the 350 (G35 and other 35 variants) don't have any notable digs either.
Not exactly scientific, but if forums are any indicator, there hasn't been much bitching with respect to the 3.5 motors or cars with them.
Pathfinders, not so much. Crappy mileage and expensive replacement parts.