I use BrokenOut with GoLauncher, GoLocker, a whole BUNCH of running widgets, RomToolbox Pro running CPU profiles (1188/600 screen on, 400/600 screen off with smartassV2 governor) along with Noop scheduler and JIT compiler and a few more performance tweaks.
Battery life is same as stock, about 12 hours standby or about 4-6 hours full throttle
Performance is AMAZING. It NEVER slows down, its always smooth, and I havent encountered a game yet that it didnt play smoothly (veggie samurai, Gun Bros, ShadowGun and a couple others that my girlfriends samsung running at 1.0Ghz had trouble with all play smooth as butter on mine)
useability is better than stock, whether its built in ROM features or simply features accessible because of the ROM. The ONLY affected system is Bluetooth as far as Ive experienced (and I havent used it myself but almost everyone has reported it so Im guessing my phone will be no different)
Stability is excellent. A couple of random restarts in the beginning (most likely due to my own actions though) but since then no problems
couple of recommends. DONT run LG Connect Optimizer or the factory No Frills CPU Control (I have a feeling that they conflict with other apps like RomToolbox or anything that does the same functions I.E. CPU speed controller, an SD card speed increaser, build.prop modifications etc. because as soon as I deleted them and JUST used RomToolbox for things like CPU speed control I havent had a problem with random reboots). I would recommend paying the $5 and getting Rom Toolbox Pro. It replaces something like twenty apps and does a better job at them than the original apps did. AND it has features that you cant get elsewhere. Seriously its an awesome program.
It has been a FINE ROM for myself and honestly since we dont have ANY other options besides stock (IM waiting for CM9 or equivalent) AND this came out VERY quickly compared to the release of the phone, I am really amazed that it functions as well as it does.