I have seen both. Mimi has a great body and is professional with her service but can report that she is only in it for the money and acts like it as fellow posters have already noted in this thread. I rated her a Neutral.
Zasha is similar. Her body isn't as hot as Mimi's in my opinion (I understand this is subjective), but did seem to interact a bit more and was more proactive than Mimi. I rated her as Positive but looking back was probably more a Neutral. Neither would be regarded as my top punts.
If I was to see only one of them again, I would probably go with Mimi.