I've played 50k hands at 2NL 6-max zoom on
pokerstars, all within the last few months, and my win rate is 6.5bb/100 (so $65 up total).
The thing to note about this game format is that everyone plays extremely tight preflop. Most players are never 4bet / folding, meaning they'll only 4bet hands that they're willing to stack off with, and this range is usually KK+ with a few occasional AK combos mixed in.
You can take advantage of this by light 3betting and light 4betting, but make sure that your 5bet shove range is only KK+. I'll typically 3bet a lot of marginal hands on the BTN, including suited connectors, low to medium pocket pairs, suited Aces, suited Kings, and any hand that you'd open UTG is something I'll 3bet on the BTN. I keep the same sort of range for re-steals (SB vs BTN, BB vs BTN and BB vs SB). I'll also often 4bet / fold a lot of junk hands. So if I open raise to 6c with a hand like ATo, someone 3bets me to 18c, I'll often 4bet to something like 40c with the intention of folding to any 5bet shove. You'd be surprised how often this works against nits who will only give your 4bets action with KK+.