I also heard that when you are lying in bed at night, trying to sleep, you can hear the mechanical valve clicking. I’m a bit worried it might bother me. What do you think?
If you live in a very quiet home, especially out of the city, which doesn't have a forced air HVAC system, you might hear it pretty well. If you are the sort of person who is driven mad by dripping taps or mice building nests, you might not do so well with it. If, like most people, you find that the noises of daily life fade into the background, you'll likely not be bothered.
I have a mechanical watch which I can only hear when I'm in a quiet room. Sometimes I'm not sure whether I'm hearing my watch or my valve, but neither keeps me up at night.
Warfarin for me, has turned out to be no big deal at all. I'd think it might be even less of a big deal for someone who already takes daily meds. I take a fair beating at work and play and while I seem to bleed a little more, and bruise more readily, it's not dramatic. I do try not to hit my head as much as I used to! (That doesn't stop me from running, bicycling, motorcycling, rollerblading, camping, swimming, sailing etc., etc.).
Years ago, I had a dentist advise me that my wisdom teeth, which were having trouble finding space, should stay in because researchers were on the verge of perfecting a method to transplant wisdoms into the place of molars. I would have a mouth full of spares, he said. One of those wisdoms became massively infected because it always remained partly under a flap of skin. When it was being pulled, the new dentist asked why it hadn't been taken out ten years earlier. I told him about the transplant idea and he said "yeah, that never really worked out".
The point of my story is that medical advances, even when they seem quite likely, are never guaranteed. In my case, there is a very good chance that the massive oral infection helped along the degradation of my aortic valve too!
I would never recommend choosing mechanical because you expect warfarin to be succeeded soon as the anti-coagulant of choice, nor recommend tissue (which we should always remember is not a 'natural' tissue valve in any way, it just uses biological materials in it's manufacture) on the promise of easy future replacement. I would always recommend basing your decisions on what you know is safe and available today.
They are each good, and you're probably leaning one way or the other. Your choice will be right for you.