i run a little tighter than most of the full ring regs on this site, about 12/9/3 but I'm currently beating 100nl on FTP for about 3.5ptbb/100. I remember reading it somewhere on this site but preflop stats are just a preference, all the crucial decisions come on the later streets. I don't have any experience running 9/7 but if you correctly use your extremely tight image in the correct spots, and can play well postflop, im sure you can beat most regs at the lower midstakes. My flat calling range is essentially only pocket pairs and the occasional sc IP. I will also sometimes just flat AK or AQ against a relatively tight EP raiser.

I've also been thinking about good spots to 3 bet light pre, as i think it could be extremely profitable in games where 3 betting is very well respected, but i usually just do it against CO or button raises. this is an area of my game i need to work on so i would be interested in hearing how you are attempting to morph your game.