General rule I use is Max weight, overstable (Nuke OS, XXX, Trident, Firebird) if I want to smash my forehands out there for distance around 275-300. But I had a great conversation with Jeremy Koling at the 2012 BSF last year, who I believe currently holds the record for forehand distance? He completely changed my perspective and my technique.
Old way: Before meeting "Big Germ" I would take my max weight/stability driver and snap hard, usually rolling my wrist to the left RHFH. Because it was overstable it would come back but this was not smooth.
New method: I now focus on the nose angle, and throw a smooth snap, gently rolling my wrist towards my back then a smooth release. The disc is released with a hyzer throw, and I try to throw a moderate stability disc like the Halo in a max weight for distance, or the Saint for a gentle turn over. I still use the big stability discs, just not to compensate for bad form anymore, but to achieve a particular outcome now. I never could Flick a putter or mid until I grasped this technique, now I can use both when needed.
Watch this video (
https://www.youtube.com/watch?v=OjmD6wVp6Nw ), and any others you can find with Jeremy using his forehand. It's just so smooth and effortless. He uses a Surge in the past, probably a D1 now.