Actually Ann is probably the easiest one, she is just the one where he starts latest
But yeah, of these four, Ann will probably be the "highlight" ... as usual. But it was also promised there would be more to come (Kiras daughter for example).
I personally find it sad when getting someone into bed basically ends her story. I prefer stories where that is part of it, but not the end goal. There have been some good examples of how to do it right, so even IF Ann is the last of these four to have fun with Max, I hope it doesn't mean there won't be anything after that with the others.