I won't even pretend to speak on the universal characteristics of dipoles and when they should/should not be used. I'll just mention my personal experience. I auditioned a pair of Definitive Technology dipole speakers about ten years ago in a dedicated listening room in an audio/video store. They seemed to know what they were doing, so I don't think that it was set up wrong. Anyway, I listened to a selection of music that I had brought with me. The music seemed to be coming from the room that I was in, but the vocalists sounded like they were singing from a room behind the front wall. Probably a bad description, so try this one...it sounded weird. I did not like them at all. I thought that I would. I even went to the store expecting to buy them. However, after listening to them, there was no way that I was going to buy those.
Just my experience.