First.
Lets all be respectful.
As for "Fit and Finish", the last Chevrolet I purchased was my SS, which I took delivery of in late '98. So, I am not a "recent buyer of a GM product".
That being said, while I understand the question, (being directed towards those who have purchased newer Chevrolet/GM vehicles) I feel it's also possible to listen to and ain some insight from the thoughts and opinions from the casual enthusiast.
My brother owns an '05 C6, and I can tell you, the fit and finish has greatly improved!

And having attended numerous auto shows and witnessed the fit and finish of the new Chevrolets, (Malibu; Corvette; etc.,) Cadillacs (STS; CTS: etc.) I can form the opinion that GM has really got their game together.
Again, I understand the original question. But, lets accept all thoughts and opinions, and respectfully accept everyone's thoughts.