I sometimes feel like I'm in the minority, but I'm and advocate of towers. For HT also. Your space is small, so bookshelf speakers would probably be fine. IMO however, even though they play loudly, they just don't do it in the same way. Towers are not just about bass extension, which is certainly a nice side effect, as you mentioned with direct mode. I have a pretty large space, and have found that small single bass driver speakers just can't excite the airwaves in the same way. Small speakers sound small. Even though they can be loud. Also imo, the look of towers is more elegant than speakers on stands. The good thing is, there's more than one way to skin a cat. Metaphorically speaking of course.
I remember comparing a couple of speakers and while listening to Eagles "Hotel California" I was thoroughly convinced that the larger speakers were better. The bass line was wonderfully full/rich.
In comparison, the bookshelf speakers were not there. The bass was not absent, but the sound was not near as rich. After that, I put on some Steely Dan, and while the bass was definitely fuller on the tower, it was tighter on the BS speaker. I think this is a general tendency. It may not be the case for every model/manufacturer, but I have seen it often enough.
IME, towers almost always have more resonance due to the physics of larger panels. Uber expensive tower speakers will go to great lengths to eliminate those resonances with bracing, etc. Very inexpensive towers are likely to have truly offensive resonances (which start to really dominate, if you crank them).
But among more mainstream products (like you are looking at), the added resonance almost always comes across as a richer, fuller sound.
Totem designs their speakers with cabinet resonances as part of their design.
So, IMHO, it gets down to personal preferences. How important is tight to you? How important is full/rich bass. I am firmly convinced that I could take people in a blind test and get a high preference for either speaker depending on whether I used Eagles or Steely Dan for the evaluation! This is why we should always bring our own music rather than listen to what the dealer has on tap. A salesman may have found the perfect song to showcase his most profitable speaker!
However, I would be very slow to tell anyone that they would be better off with bookshelf speakers than tower speakers from the same manufacturer/series of speakers.
However, if we look at it from the standpoint of spending equal money, the added performance from higher quality drivers is pretty compelling. The SVS speakers are a great example. You can get Prime Towers for $1000/pair or Ultra BS for $1000/pair (though you should look for B-stock, SVS B-stock blemishes seem to be of little consequence). IME, the mid-high frequency improvements of the higher grade drivers will win the day. The bass may be a closer contest, but as long as you have a good sub to play up to ~80-100Hz you won't miss much.
Halon,
I would recommend that you do your own in home test! Float a pair of the Prime Towers and a pair of the Ultra BS speakers using SVS's no-risk return policy. Get them both in your room and make your own decision.
I think the biggest problem is that you will end up deciding that you want the Ultra Towers.
Honestly, reading your comments, you are happy with your SCS/SBS, so why not go ahead and save for the Ultra towers. You have stated a preference for towers and if you have a strong orientation toward towers, you probably won't really be happy with BS speakers even if they sounded identical to the towers. No judgement from me - I know if I didn't like the way a speaker looks, I could never really be happy with it!
