i was concerned about the dump valve too. I finally decided to go for it after I was on my last trip, working along the bottom and changing depths as I followed the topography. I had to tilt way up to dump. Granted, part of my problem was that the SMS75 doesn't dump gas well without steel tanks pulling down on the rails, so, using al80s clipped to my belt, I had to sometimes reach back and squeeze the bladder by hand to get the gas upwards toward my head. That's a long way for gas to travel, a big bubble free to move from my hips to my shoulders. So arrises another issue, trim is less stable with the long-back wings. but I digress. I spoke to patrick about the dump valve placement, and he said it was conceived with the frailty of industry dump valves in mind. If the dump fails somehow, if it's at the bottom, you can tilt up a little to trap gas and head on out. If it is at the shoulder, well, you get all those stories on CDF about trying to use an SMB, their drysuit, climbing walls underwater, and calling for double bladders. SO, I finally decided that with the success of the stealth, I can learn to use the butt dump if all those other people can. I'll let you know how long it takes me to get used to it.