Summary: Great little machines. They've become the standard PC for the sales and operations people at my company. Compact, quiet, and mountable to the back of most monitors so you can keep desks free of clutter. Have had one NUC out of about 15 so far with some issues out of the box but it looks like that was most likely bad ram.
Pros: Small, quiet.
Cons: Biggest downside is too few usb ports. The newer model NUCs have fixed this.