I'm creating a low power outdoor sensor unit and am on the fence on whether to use the Boarduino or the new Arduino Micro. I prefer the Micro as there's no setup involved, but I've created a few Boarduinos with success and will use it if necessary.
I've found that when I power the Boarduino off a regulated 5V supply directly to the 5V and Ground pins and put it into a deep sleep, it pulls approximately 3 mA. That's about 10x better than what I can do off an Uno when hooked up similarly. So, between the Uno and Boarduino - it's a no brainer, the Boarduino is in the lead.
However, I'm intrigued by the Micro. It's better for me if I can use the Micro as it's an off-the-shelf device that will make construction a lot easier. However, I'm wondering: If I were to power the Micro through the 5V and Ground pins and put it to sleep, would I see a current draw more similar to the Uno ... or the Boarduino?