Both. It depends on the tool. Cordless large? I went with DeWalt brushless, but it was a close thing. Cordless small? I went with Bosch, glad I did, DeWalt's support of their 12v has been sad. For primarily irrational reasons, I'm not a purchaser of Makita or Milwaukee cordless.
I have DeWalt, Bosch and Milwaukee angle grinders, a DeWalt and Bosch jigsaw (prefer the Bosch), Bosch and DeWalt routers, etc...
Other than the advantages of a common battery platform, I go for the tool which is best suited for my needs, thus the variety above. I also have Porter-Cable (circ saw, sander), Milwaukee (Sawzall, corded drill, heat gun, grinder), Makita (compressor), B&D (corded drill), Festool (jigsaw), Metabo (die grinder) and Mirka (sander) in my arsenal.
There aren't very many small power tools on my to-buy list now, but both DeWalt and Bosch have places on it. (So does Makita.)