My own fingers...not so much. Hubby's fingers...very nice. Hubby's tongue...we have a winner. As far as masturbation goes...vibrator, all the way.
Never having been a woman, I can only speculate that if the guy is not as exciting as your own hands or toys, he can be replaced. (My phone number is available on request.) Children are an issue for some women. Theoretically you could fuck just twice in your whole life, two children would result, and the species would go on. Two successful fucks isn't a whole lot over a lifetime. Plus, in these modern times, if you're a confirmed lesbian wanting children, there's the artificial insemination route.
if youre having more fun with your fingers than with your partner you should open up the lines of communication to make things more pleasurable for both of you
I looked at your bestsexualpositions.org site and just have a short comment: Although I didn't go all the way through your site, it would benefit from photos or drawings. Maybe it's still under construction?