I don't mean to rehash and old thread but Ben's quote from above is an important statement that has been argued for a long time.... Well Ben is actually in the know and I'll take his info about anything Evans as gospel. So, there IS infact a difference between the different hydraulic heads beyond just their color. Care to elaborate or possibly set up a formal scale rating each 'color' or model from say least to most sustain for example? Evans doesn't even lightly discuss this anywhere that I've seen on their page.The Red Hydraulics are my favorite out of the Hydraulic line, primarily because they're much closer to a G2/EC2S but still with a much shorter natural sustain. This has everything to do with the film combination (all of the films used for the various Hydraulic models are different). They respond at a wider tuning range than the other versions as well.