I use Thunderc recovery and it didnt Brick my phone but it didnt run perfect either. Zefie's CM7 for the S is better then what he left for the V but still has some issues.
I had oddly timed lag in the UI and wifi didnt like to reconnect.
Does it reboot by itself at all? Problems with drivers at all?
Also do you have alot of apps installed on it?? Do they run smooth?
Would it brick my phone if i tried Zefie's Nightly rom? Which is for the Optimus S.