For now, a mutual friend is my favorite, but we've been in the lifestyle for some time and I know that the guys sort of cum and go over varying lengths of time.
Successes of failures? You mean with the other guys? (I hate the term "bull") Too many to summarize here, but the most recent was a failure. Sometime around August I had a date with a a guy and we met at a restaurant. We went out to my car and began kissing and fondling. I opened his pants, planning to go down, but as soon as I touched his cock he let out a gasp and dumped his load all over his stomach. He was certainly not "bull" material.
I don't know what you mean about what's my preference.
I always choose who I am interested in, but sometimes my husband helps me find guys.