I have the Ping G30 Sf Tec (12 degree), G Sf Tec (10 degree) and a G400 Sf Tec (10 degree). All 3 are very good for my swing. All are the same distance wise. The G400 (445 cc) is marketed as more forgiving and the G Max is more forgiving than the G400 and any other driver out there. Do I notice more forgiveness? Not really.
I like a draw bias driver, but as you say the G Max and regular G400 don't come in a 12 degree loft. I'd try the G Max in 10.5 and loft it up to 11.5 degrees and see what you get. Also, you could try the G400 in the Sf Tec in 12 degrees and loft it down to 11.4 degrees or down to 11 degrees and see what happens. Lofting down will open the face and may negate the heel weighting draw bias.
Worth a try to see if they perform better than the G25 for you.