I just got mine back from the full-house treatment. Very happy with it so far. As it came from the factory, the slide to frame fit was fantastic. The trigger was not.
For a stock MilSpec, at a minimum, I would upgrade the trigger group (trigger, hammer, sear, disconnector, leaf spring - Cylinder and Slide sells a great kit for this, works very well), the sights (to Heinie's or Novaks), and perhaps the beavertail (to Wilson or Baer - I have problems engaging the Brown properly).
I'd also stick some skateboard tape on the frontstrap (one sheet will cost a buck or two and be more than you need - cheaper than checkering and easily replaceable).
Also get some Wilson magazines. Well worth the money and very reliable.
Did EB grip safety, EB thumb safety, EB tactical ext. mag release, CMC trigger, CMC hammer, CMC sear, disconnector and sear spring, tighter bushing, heinie sights, and checkered arch MSH. Most of that is just because its what I like. It shot fine out of the box.