Just finished. I really liked the game, though there were a few really annoying bits, like the forced combat.
Was anyone else really bothered by the fact that you only regen the first battery if you run dry? Seems to make the extra battery upgrades pretty useless. You just use candy bars if you need to get an extra-long stretch of invisibility, knock out two people in a row, or spam the Typhoon. I would have had a lot more fun with the game if it all came back (I think everyone is OCD enough to be a little reluctant to restore energy unless they need it).
It felt a lot like Vampire, and I'll probably go back through at some point for Pacifist and Foxiest (though I already went through mostly stealth).
I suppose that if you're trying to max out on augs, you ought to go through all stealth-like while still knocking out as many guards as possible. Terminator-style doesn't seem to give nearly as much experience. Plus those guns really hurt on the highest difficulty. I assume that you can take a lot more damage on lower difficulties, but does the difficulty matter at all for stealth?