With Ann it's extremely YMMV, if she warms up to you she would be better than Irean given the youthful body and natural (but smaller) boobs. Irean on the other hand is very consistent, you know what you get. Read many reviews saying Ann is quite restrictive and I was concerned, but I booked anyway given the banger body. Had an amazing time with Ann and would 100% repeat.
Agree with the YMMV. I have read reviews where people received different services. Maybe it is time of day or something else. The website services are not reliable.