I have a human valve, about to be replaced 6/23/10 and picked the ON-X valve for a variety of reasons in consultation with my surgeon. One, he likes it and has experience with it, which sounded good to me, two, I have noise concerns regarding mechanical, so even if it's the placebo effect, my mind is more at ease with the ON-X. Also my doc likes the idea that pannus may not be as much of an issue with the ON-X vs some other valves and he also likes the anti-coag studies that are being done with the FDA, given my active lifestyle. He also does other valves too, so I imagine he makes the choice based on each individual patient.
As an aside I'm in healthcare as well, and am constantly dealing with sales reps from medical companies talking about how their product is the best. Usually I find there are a few products in each category that could be considered "equal" best, or at least similar in performance, and as technology improves, so too does the "best" product or products in the field. So what may be the best product I fit a patient with now, will be different 10 years from now. Doesn't mean the ones now aren't any good, but things can always get better as technology develops.
Since I'm not a heart guy, I can only imagine that surgeons are happy with valves when their patients aren't dead, live a full life, and are happy with the one they have implanted. At the same time, I'm glad I did human in the past, as the options in mechanical now are more suited to my lifestyle. I'm glad I have had the luxury to choose, although i imagine I would have found a way to live how I wanted if I had received. mechanical 8 years ago