Zaned, I'm increasingly a fan of thinner strings. Theres a certain trade off that has to be made for mass; too little and your tone is unredeemably thin, and theres not a hell of a lot you can do about it further down the chain. Too much mass and theres bloat you cant get rid of and overtones suffer as they're weaker and fewer on the thicker string.
There is the matter, crucially to me, of tightness. Its natural to think that tightness in tone comes from physical tightness in the string. Thats one way, but tightness can be controlled and imparted with good playing. Clear ringing overtones cant, if the strings thickness is fighting them.
I used to use a 66 on the A# (still to a 12 on the high C). I'm down to 56 now. I think thats about right. For E to D I use 10s on 25.5 or 10-48 on 24.75.
The other factor in (comparatively) thinner strings, is you've got somewhere to go if you dig in. Hit a thick string weakly and it responds poorly, you have to batter it to get it to respond. But hit em harder and dig in more and they dont really give any more. Tight, more controlled and lighter playing on a thinner string can get the same tightness that hammering a heavier string gives you, but you can still get huge sounds digging in hard. It gives the guitar more dynamic range.
