I am not sure. He seemed to like the Sherwood Magnum a lot, though he dove with a US Divers reg when I was diving with him 4 weeks ago. I am not sure the full realm of his experience, though as said he has done rescue diving for years, and to my understanding comes highly recommended in that realm. He also did rescue work for the Olympics Kayak events on the Ocoee and was highly thought enough of to be asked to go to Australia. I forgot to ask him if he was doing anything for the Olympics this year. He's a very busy guy though so perhaps not. He's kind of one of those people that doesn't say a whole lot but when he does, everyone shuts up and listens. I haven't decided on which reg I'm going to buy. I have a new Aeris Atmos Sport that I had to 104ft in Grand Caymen and loved, but his comment was always have a backup regulator if not a full set of gear, so I have been looking at Sherwood, Apeks, Aqualung and the new Dynamo Regs that I saw a posting for on here and requested info on. His comment just sort of stuck in my head and made me consider Sherwood. Apeks and Aqualung were really my only considerations up until the recently.......though I'm kind of love struck on the Apeks Black Pearl.