Can't really add to what's been said.
I was hesitant about DS9 as well, but ended up buying the box set of the entire series on DVD after having seen episodes here and there on the different collections series (Captains, Q, Klingons, Time Travel) and it has become my favorite Star Trek series.
Not only great character development for the main crew, but the villains as well. Hello...Weyoun!! Hated him at first then he becamse on my my fav characters on the show!