i stacked my cabs like this:
one cab sidewashing the drummer, and balance the other on its side, aimed towards me. never had a problem.
let the soundguy figure out HIS thing, esp the crappy places around here...i was able to keep myself and the drummer locked in pretty much no matter what. and, as mentioned, was always able to keep a handle on the icepick to the head frequencies.
when able though, i LOVED having my stack behind me roaring like a freight train.