as a high end tweak and custom intaller/designer guy myself, who's also WAY into home theater, may I suggest that likely the "di-poles" would be most pleasureable for movies over the long run...that is if you aren't "anchored" in one "center seat" or whatever. If it's just you sitting center, and you do mostly multi channel music, and don't have to content with practicality issues(i.e, speakers in the way on the floor), sure you could do fine. The soundstage in the rear will be lower and much more localizeable however. To me, for movies(if applicable), this isn't as good, and often a distraction.
Overall, I'm an advocate of placing surrounds high above your listening possition, depending. However, audiophile purist types, who are into multichannel music will take their pinpoint sounds from all speakers as a priority, even in the "back surrounds"...thus they chose "dirrect radiating speakers", either mounted or on the floor/stand.
If you're in the latter camp, and again it's "just you" listening in a center seat, I'd rather see you do smaller monitors(matching mind you, as close as possible) mounted above head and maybe slightly behind your possition, as a general guide-line.(must be placed where it's coupling with the room the best for balanced matching sound with the mains, ideally. Then you should amp/toe/point for tonality. Placing smaller speakers up above your head will help keep them from drawing you out of the main soundstage(up front!)..this is critical in my experience! You don't want a rear speaker "droaning in your ear", saying "I'm right here, so pay attention to me!!!" This isn't good, and tiring soon there after.
These reasons are whey I personally like Dipoles for movies, where you just want "ambiance", "fill", "surround" and enveloping info as a priority, not pin point immaging, which isn't usually possible unless you sit dirrectly between them, with probabaly a rear center as well. Even then, it's if'y depending on mixes, etc.
I would opt for you however "dirrect firing" if you're into music, and dipoles if more multichannel movies. Dipoles dissapear and integrate easily, and don't draw attention(are more flexible, etc) to themselves, while dirrect offers more solid info, trickier soundfield, and less placment chioces most offten. They basically both need differnt aproaches...not to mention differnt set up locations, both for imaging and "best balance of sound".
I think what I said makes it simple...dirrect for music, di-poles for movies.
