I really do like that modified 69 type of position, but if I had to chose, I prefer to be the one on top. The stimulation is fantastic, from start to the "finish" and the afterwards.
Unfortunately, given safety concerns of staying clean, it's not something one can experience often...there's a limited number of people I've done this with. That doesn't stop me from having some truly, really, wildly decadent fantasies about this, though!!!
What is wonderful about my situation is the fact that there is a small, but varied group of women with whom I have have had fantastic sex and love to share with my husband who is also the minion of my Domme-self.