I had mitral valve regurgitation, too, and was scheduled for either a repair or a replacement. I had the surgery last month and they were able to do a repair, which is nice for me. I hope you are also able to have a repair, Ronda, but even if you have to have a replacement, maybe my experience may help. Discomfort-wise and pain-wise, I don't think there is much difference b/n a repair and a replacement, it is the same surgery in terms of opening up the sternum, etc. I can tell you, the whole experience was a lot better than I had anticipated in almost every way.
I was afraid of lots of things prior to the surgery, but most (like the breathing tubes) weren't nearly as scary when they actually happened. And I had very little pain, certainly nothing like "horrible" pain. I don't want you thinking I am stoical or pain tolerant I am really a pain wimp. But like Sue I'd use the term "discomfort" rather than pain and for me it was not really bad discomfort either. They are very good at managing pain in the hospital these days. I got pain medication there like clockwork, I do not know even now whether I really needed it -- I never had to ask for pain medication, because they never let me develop any pain before they were back for the next dose. I was sent home with Darvocet which I only used for the first week or so to help me get a comfortable position to sleep at night.