"That said, V1 versions are history and there's no point in discussing them; they will become unusable after mesh rolls out to the grid. As far as V2's are ocncerned, you obviously need to tweak your settings when running LL's V2."
first: v1 based viewers are more than 2x as popular as v2 based viewers. This is by users whos have tried several viewers adn conscioulsy chosen. That being said, some viewers seem to work better depending on the computer being used. For most people that will be v1 based viwers, but not always.
One problem with v2 is that it likes to reset graphics setting on logging in, so, if you have an average system you usually need to go to graphics settings and readjust for what works for you. Sure it wont look as good wehn you lower graphics settings, but tht just part of v2.