Here's a picture of my two Raspberry Pi 2 boxes, both running headless and wireless.
One is running Raspbian, installed via NOOBS, and the other Fidora, a remix of Fedora 21 for Raspberry Pi 2. It turned out that Pidora doesn't work on the Raspberry Pi 2, a fact that is extremely well hidden on the Raspberry Pi web site.
I have set up test buildfarm animals on both of these. But something odd is happening. They are both getting intermittent failures of the stats regression test. Sometimes it happens during "make check", sometimes during "make installcheck" and sometimes during testing of pg_upgrade (which in turn runs "make installcheck").
These machines are not anything like speed demons. Far from it. But we also run other slow machines without getting this happening all the time. So I'm a bit perplexed about what might be going on.
Incidentally, if you want to play with one of these, I do recommend getting a starter kit from Amazon or elsewhere. It's probably cheaper than buying everything separately, and gets you everything you need to get started. Well worth the $69.99.