Yes it is.  It was formerly called Phoenix Rising.  I believe the reason he recommended that you try it is because it now has over/underclocking functionality built into the miner.

FWIW, I mine with a single 6870 and AB works fine (just as it does for you with 1, 2, or 3 cards).  I don't overclock, but do underclock the memory to 300.  AOCLBF is the miner I use, and it's an awesome miner, but I am unable to underclock the mem to 300 with it.  I suggest you give it a try, it might work for you.