Well, I keep my grinder and one of my drills in separate Plano tool boxes. Everything I need with it is kept right with the tool. Sure saves on looking for the wrench for the grinder.
I try to buy hte best tool that I can afford at the time of purchase. My grinder in a Makita 4 1/2" that I bought about 10 years ago, and my DeWalt drill is about the same age. I've just been noticing that the lights flicker slightly in the garage when I run the drill. It hasn't run really hot or anything, but I figured I missed something in terms of upkeep.