I suppose if you're first experiencing the series through the anime, it isn't too bad, but it doesn't resolve the story at all. However, the manga is better in almost every single way, and the anime doesn't even cover half of the manga's story, plus it makes several IMO unnecessary changes. While some may be disappointed by the ending of the manga (I wasn't), it's definitely worth a read if you don't dislike harem series. I personally recommend reading the manga and then watching the anime episodes.
But yeah, like most harem series, don't expect the main guy to make a decision quickly. However, one major factor about the series that I like (and I imagine might influence a few of you) is that the main guy doesn't get randomly attacked by the girls for things he didn't do nearly as often as in other series. Well, he does get attacked in the anime-only stories, but not so much in the manga.
Again, read first, optionally watch second.