Just read this thread now.
I would like to offer another viewpoint.
I am convinced that inate physical compatibility is a key factor. No amount of in-the-sack-performance-expertise is going to trump mother nature.
I was married for 10 years and am now happily divorced for 3 years. Knowing what i know now, it is clear to me that my wife and i were not amazingly sexually compatible. The sex was ok (at the time i thought it was great) and it was not as often as i wanted. I had to beg for it EVERY time. I was thrown a bone on average 4 times a month. When we had it, i thought it was great and i was satisfied.
Boy was i wrong!!!! After divorce, i have been in numerous relationships. (Not one night stands). I now know what i am doing in the sack and i can see that empirically the quality of the sex depends on the compatibility of the pair. My performance or ability doesn't vary -- rather, the quality really depends on the compatibility. I disagree with some posters who said that if us men knew how to handle our women they would be coming back for more.
Compatibility is not something that can be changed or adjusted. It is what it is.
My point is that one needs to marry someone that one is compatible in the sack with. Just like you need to see eye to eye on other things like: lifestyle, religion, child-rearing approach, handling finances, etc.
I would like to get married again but will not settle on the compatibility issue in any important area.