I was asymptomatic enough that there was some question early on whether I was going to need the surgery. But some people just have a high pain/discomfort threshold, and although I had some angina, I presented oddly (as do many women) with only some tension across my shoulders. A year ago I did 6 minutes on a treadmill without feeling anything; my last stress echo didn't include the treadmill because the doctor who was monitoring me would let me get on it. He was afraid I'd buy it right there.
Since surgery however, I already feel immensely better, just two weeks post--to the point that I'm only now realizing how bad I felt before. So you may be one of those folks who won't know until you're fixed just how broken you are!
Every recovery is different, of course, but if all goes well you should feel noticeably better as soon as your chest stops hurting (and that's really more like feeling sore and bruised to me, rather than painful).