This thread had me thinking more about IS/B, so I tried it out last night. You can read my account HERE (Pirouette's Fun with Pheros - #29 by Pirouette). I usually use two sprays, but I used three last night. To me, the effects are subtle and not as dramatic as IS/A or MX 1-, 2-, 335. So I guess I lean more towards IS/A because of the self-effects and the reactions I get from people, men and women.
With IS/B, I notice that men study me more and are more attuned to my reactions, facial expressions, more reassuring, even kind of fatherly. Trying to make things easier for me. Whereas, with IS/A they notice me in a more positive way, are more accomodating, but in a more subservient/eager way, and just engage with me in a more energetic manner.