Well thought I would add my experience to the mix..
So far we have had the BOT running on our 5 BF3 servers full time since the 18/12/2011, they are a mix of game types and server sizes maxing at 42 (we used to run 64 slots but got fed up with the crashing), they are all running on a dedicated server from killercreation.
I host the B3 bot on a windows based cloud server using an xampp installation, on the same server I host B3 for 1 MOH,3 cod4,2 waw and 4 mw2 servers.
I tried the BOT in it's early release stages for BF3 but it was a bit temperamental, just stopping responding to commands etc.
Now I would like to say that it is in excellent shape from my experience we have in excess of 35000 entries in the database across our servers, the servers are full for at least 18 hours a day and a couple are active some days 24/7.
I have no plugins active other than the normal install, and all of the function work ok and I have had no B3 issues from my admin team.
Cheers
Flatsix
Head Admin
Old Gits Having Fun
http://www.oghf.org.uk