Ok, finally got to spend a little time comparing the Aperions to the KEFs. I was a little concerned at first that I might feel like I over spent on the Aperions, but after the comparisons I don't, thankfully. However, I do think these iQ5's are a good pair of little towers for the money I paid, $400.
The veneer is very nice looking. The fit and finish of the speakers is great, well put together. They only weigh 22lbs, but they are not big speakers at around 33" high, less than 7" wide, and about 10" deep. Because of their size, they actually seem hefty. The cabinets sound very solid when rapping on them.
I had probably 20+ hours on them when I finally did some comparisons.
I used-
Blue Man Group - Above (How to be a Megastar)- great for sound stage, imaging, and percussion
Peter Gabriel - Growing Up (UP)- listening to this song you swear it is in 5.1, I don't have any other stereo source that gets into your head as much as this one when in the sweet spot.
Dream Theater- Just Let Me Breathe (Falling into Infinity)- need a little rock with lots of kick drums...
Nightwish - Wish I had an Angel, Amaranth (Once, Dark Passion Play)- female vocals, power metal, let's push it a little.
I did not move speakers back and forth, as a result some of what I heard could possibly be improved by futzing with placement some more. As usual, keep in mind I don't have a lot of experience with dozens of speakers or have a golden ear. Almost all listening was done in pure direct mode.
BMG- the imaging seemed very precise with the iQ5's, and the soundstage was good, it went just beyond the speakers (better than the CSW they replaced). They are rated down to only about 43hz, so at first they sounded fine. But then I switched to the 6T's, and it was kind of like "oh, that's what I was missing". Of course that could be remedied with a subwoofer. The imaging between the two speakers was very close, however the 6T's seem to have bigger soundstage as they seem to envelop me more and some of the drums seemed like they were coming from further out beyond the speakers.
PG- I thought Growing Up was good with the iQ5's, but didn't seem quite as impressive as with the 6T's. The 6T's seemed more lively and a little more detailed. I checked the sound level, and they were within about a db with the 6T's a little quieter actually. That was one thing I noticed- I tended to prefer the 6T's even when they weren't playing quite as loud as the iQ5's.
DT- Once I got into the heavier stuff here, I started to notice the iQ5's seemed a little brighter and more forward than the 6T's, and the 6T's seemed more 'laidback'. I guess I don't know for sure if I am describing them right, but that seems to fit what I was hearing the best. The iQ5's seemed to lose a little bit of their imaging here- with the drumset I noticed drums, snares, etc being used all over the front stage witih the 6T's. On the iQ5's they seemed a little more focused in the middle and not as 'all over the place'.
NW- Not much for soundstage or imaging here, just loud rock. These songs have some pretty good bass, which was noticably absent on the iQ5's. But then again, for background music it wouldn't matter so much, as there still is decent bass here, just not real deep. The female vocals sounded good (on my old CSW's they sounded 'off' for some reason). This was also the point I turned them up to 100db briefly, and for such small towers they held their composure rather well, there seemed to be some strain there, but not nearly as much as I expected.
I also have to add that I did not do direct comparisons with anything acoustic, but I did listen to a few things, Eagles, Norah Jones, 10000 Maniacs, and the iQ5's sounded great with those.
All in all, I am happy with them. They will go into a cabinet in our main living room where we usually only watch tv, tv dvd's, and occasionally music, so the expectations are low. But for the money I think they will do well. And while I favored the 6T's quite a bit, they also cost $1000 more (so I better like them more! Or am I just brainwashing myself?). I wouldn't hesitate to recommend KEF as a speaker to audition, and would be quite curious about how the iQ9's handle. I know they can be had for under $900 now, and are probably quite a deal.
I have heard others mention that the iQ series is great for acoustic, jazz, and not that great for rock. I could see why some would say that, but it's not like they fall apart on rock either. I did not watch any movies with them, just tv shows, so cannot comment on their use in a home theater (they did fine with the tv shows).
That's all I got, but it's probably been long enough...