I think on a broad view there are differences. Not necessarily in terms of libido, but in a more broader definition. An SP will enjoy sensory experiences, even if it was just a micro degree, more than an NT. All my NT friends can go for months without sex without going crazy.
I can't go for months. No way. I can barely go a couple of weeks. And there is not disputing me being an NT. Well, you could, but it would be pointless.
Also, I think the fact that you have chosen to view sex as only a sensory experience is throwing you off. S functions are far from the only function involved in a sexual scenario.