Does anyone know if its better to use the plextor AWS (auto write strategy) or to leave that off? And then there are the options on AWS overspeed and downspeed, I have no idea what those mean.

I’d say forcing AWS is good because the stored write strategy for any particular disc may be wrong or edited or whatever. So by forcing AWS, the drive checks the media for the best write speed/strategy before it burns. If you enable ONLINE AWS, the drive not only checks the disc before burning, it checks in intervals, throughout the burn, to make sure that the current strategy is working.

Basically OVERSPEED and DOWNSPEED are just extremes of AWS. OVERSPEED as you may have guessed, will allow the drive to burn faster than what it is supposed to for that particular disc. Downspeed is the opposite.