I have a simple heuristic, which is: anyone who claims they are infallibly good at sex, a great lover, etc. is someone who is clueless.
This is because sexual intercourse is not like being a skater or runner or musician or any other solo activity. Sex (for the purposes of this discussion) is something that occurs between two or more people and thus is entirely dependent on each of them and on them all collectively.
We all have our own hardwired preferences and on top of those a whole bunch of learned preferences. When we are with someone compatible, this can lead to great things. When we’re with someone incompatible then no amount of purely skills-based activity is going to make it great.
And, personally, I have always found that getting inside a woman’s head is far more important than getting inside her body. The former can lead to astonishing pleasure whereas the latter is purely a physical matter, not unlike gymnastics. It can be nice, even very nice, but rarely if ever earth-shattering. But combine mental and physical and then….