I share Kendall's view. Most "kudos" are perhaps more polite pleasantry than critical acclaim, and a sincere "Thank You" is the safe, and usually appropriate answer. When I sense a compliment based on a real critique, I will sometimes inquire with some specificity about what worked, etc. - not to see how closely they were listening, but in the interest of finding out "why" they liked whatever it was. I'm always amazed at the things an audience member picks up on, in contrast to whatever I thought I/we did well or poorly in a given performance. We all hear somewhat selectively, and tend to focus opur attention on what we want to hear.