One minor peeve I have with BB10 so far is that in short order I've had 2 large OS updates. The first, part of my out-of-box experience, was about 150 MB. Then about 36 hours later another came along 3 times that size. Good thing I had Wi-Fi.
It's a new operating system and I know that I need to let the company update it, but the update process was lengthy. The first one took almost an hour of download and install time. I let the second one run overnight.