I really think it's a difference in personalities. I too feel that I should pick the best surgeon and then let him do his job. That's not to say that I trust all physicians implicitly. I've been in healthcare long enough to know better. Others like to be completely in control, or at least feel that they are. However, Marty makes a good point. Very few people want amateurs to tell them how to do their jobs. Some people even get defensive about it.
An analogy - let's say you are the IT person for a company. The company has been using Microsoft for ages. It works great, you know how to deal with its quirks, you can install it on any machine, and fix what goes wrong with it. One day Dwayne - an end user - comes in and says "You know, I've been doing some research on the internet and I hear that this new program, Flippydoodle 1.2, is better than Microsoft. It runs twice as fast, never crashes, and promises to not be obsolete for at least 10 years. I want you to install it on my computer.
If you're calm, you'll probably say, "Well, Dwayne, I don't know anything about that program, and I don't feel competent to install it or maintain it without more training. If you'd like to wait 6 months or so, I'll do some research and let you know." What you'd probably be thinking is, "Not no, but Hell No! I'm the expert. I'll have to spend my nights, weekends and holidays fixing it, while Dwayne will just sit back and blame the problems on me! I'm going with what I know and like! It's good enough for everyone else, it's certainly good enough for Dwayne!"
I'm not saying that doctors shouldn't use new technology, but if you try to insist that they do things your way, they might not like it, and an irritated surgeon might not be your best choice. If you really have your heart set on a particular valve, it's probably best to find a surgeon who routinely uses that valve. Call the company. Ask who they work with in your area. Get references and if everything checks out, go for it!