Beatability of games (based on stats)?

[graarrg]

What kind of vpips of your opponents would be required to constitute a "juicy" 6-max game? is 40+ on average sufficient to be a 2BB+/100 winner?

I know preflop stats aren't everything, but to avoid going into too much detail, let's suppose people who are loose preflop play just as badly postflop. How adversely affected is your winrate as average VPIP increases or decreases? Are there any common lower boundaries below which you should not even try to play?

I'm running pretty rough at 3/6 where vpips range from 29-45 (at one point in the day when I play 1 or 2 hours) and 35-55 (later in the day). I think it's impossible that this game is not heavily beatable, at least in the later games.

For you winners (and losers), what kind of avg. vpips are at your tables? At least with some data like that, I can decide whether I'm leaking badly somewhere or if the game just isn't a good idea (i.e. my winrate is so low that variance is unacceptable).

Thanks