Harem Hotel is plain and simply a fun game, no matter what else.
It has great sim/training aspects, and as Runey continues the story, you develop more of an attachment to each of the girls (at least I do). In the beginning, Lin was one girl I felt was most important, as she came with the hotel, so you are responsible for her - and she's terribly sweet. Ashley was entertaining, but I didn't really care for her all that much... until we saw more of her story; now I feel about her much as I feel about Lin. Similarly, the more story we get for each girl, the more emotionally invested I become with each of them.
The play structure is great, and this has a wonderfully open ended story at this point that should allow it continue for quite some time, with many possibilities for where that story will lead.
This is not only the sort of game I absolutely suggest, it is a game that can be used as an inspirational example for others who wish to make dating sim/trainer games.