Bit late to the party, but for me it isn't really about the drill itself, but the range of tools you use.
You want the same make/series across; drill, driver, multitool, saw, chaser..... whatever, so go for whichever range has all the tools you want (need + desire) - all sharing the same batteries.
I always have one spare battery on charge, and when one starts getting low on charge, I just swap it over, so I never end up struggling.
I went for Makita some years ago - unfortunately this was in the nicad days, and although I rebuilt the batteries several times and kept things going, once the drill gave up the ghost, I switched over to the new range of lithium ion, so I am in the situation of having two lots of different batteries for different tools.
Personally I would stick to the most reputable tools, Makita, deWalt, etc. the "amateur" brands like black & decker, bosch etc may have professional series, but I get the impression that they aren't quite up to the more reputable brands over their full range.
It's no use having a great drill by one make if their multi tool is tantamount to useless.