Need some new v-brakes for XC use, on bike fitted with LX/XT drivetrain. Which are best- XT V's or SRAM 9.0's?

Or Avid?

It's a case of power against simplicity (now that XTs don't squeak). XT are parallel push which evens out pad wear and produces firmer braking. But they have more moving parts and to be honest I've seen loads of parallel push brakes develop play in the arms after a while. Sram brakes are great fit and forget brakes and come with Kool Stop pads. XT brakes are also much heavier if you are a weight weenie.

thanks paul

Some XTs do squeak still (ask Mike Beckley). If you want parallel push then use LX.

Try Avids.

try disc brakes if you have mounts and compatible wheels.