"imho, the painkiller begins to shine when you tune lower, due to the tight bottom end. Its a tad too much in std tuned guitars. From C and below its just godly."
I have to agree with this. I have a set of painkillers (my first BKP) in a Mahogany body, super-strat, with a maple neck and rosewood fret board. I use to tune it to C, but now to B-standard; and it sounds very godly! Especially when the speakers on my cab start to break up.
If you tune to C-standard, I think you will really like the painkiller.