So the definition of quantify is ".....express or measure the quantity of..." So is good sex me cumming 2X in an hour session of 3x in a three session. Hmmmmm, maybe. But at this stage of my life I've outgrown the wham-bam-thank-mam romps. For sex to be "great," IMHO, you need some minimum level of connection, vibe, passion, chemistry.
I would put great sex and hot sex in the same category. I recently had an extended session where me and the provider spend an afternoon sweating, fucking, talking dirty to each other and I came 1 time. But that shit was Hot AND Great sex in my book. The passion was through the roof as it was our second time seeing each other after an extended period of time since our first session (which was a "Hot" encounter.) During this visit we were both happy to see each other and she revealed/shared some things with me about her sexual taste that contributed greatly to the passion going through the roof.
There was a previous thread regarding "last minute" appointments; to your point of scripts, planning, playbooks the "last minute" sessions can be the most erotic there are. But some need that whole planning element, which has its place but if a level of spontaneity is not included the sex will be no where near great and more a perfunctory exercise.
To re-cap; my definition of great sex is the strong presence of vibe/chemistry and passion. Then the question becomes how does/is this produced? Is it that special innate thing that's hard to describe when two people meet and you're like "damn", for whatever reason/s, this person has got my motor going. Can this be manufactured or does it need to be real on some level?