Make sure you have the set on mid panel brightness. Set HDMI input mode to Graphic (if you use Auto or Off, your gamma will be completely hosed.)
On custom, Pump the contrast up to 80 (at 86, it stops doing anything whatsoever on mid panel brightness, but you could push it a little further than 80 if you want. On my set, going above 80 increased the severity of green push, but your set may be different.)
Make sure Black Extension and AGC (or whatever it's called) are turned off. AGC in particular is an abomination.
Yes, I think it is fair to characterize the OOTB performance of my 60ST30 as both dim and dark. Mine had a horrible bump in the gamma centered around 80 IRE that turned whites into dingy dark soup and destroyed highlights. I fixed it with an external video processor, but there's no other way to fix it if your set has that particular problem, and I have seen that gamma spike on MANY owner posted graphs so I know I'm not alone, although the severity of its effect appears to vary considerably.
For reference, I measured only 19 ftL on low panel brightness and around 30 ftL on mid panel brightness. High panel brightness creates a lot of distortion in low IRE scenes and doesn't raise the peak brightness much at all, so avoid that like the plague.
I am pretty happy with my set now, but it cost me an extra couple of bills for a used VP.
I hear that the 2012 sets are supposed to be brighter.