guys, there is no way to say one reg is the "best" because there will never be any consensus as to what reg qualities are most important in determining what's best.
I think the best reg out there is one that is easily user adjustable and serviceable and one that the manufacturer makes parts and service training readily and economically available for the regs Owner. There is no "best" reg... Scubapro and Apeks comes fairly close because they both are really good regs and parts and service info, while not supported by the manufacturer, aren't that difficult to acquire. For me and what I use it for, I'll use my Scubapro Mk20/S600 as long as its still functional. I'm completely satisfied with it and have no reason to ever change or upgrade even if something thats supposedly better comes along.
If you want to know what reg is the best, go try them all and decide for yourself... thats whats important.