So glad you like them Bev, as I said before, I have the IBX-R2s, and I think they'll be my final speaker too (I do have others (Q Acoustics in another room). I find them very smooth and well-behaved. Some may say a bit too 'polite'. I find them revealing, but at high volumes I do find there's bit of bass boom - some of this is because they are on wooden floorboards with a metre of air space underneath . Have you played with their position? With rear- facing ports they shouldn't be put in the corners of rooms and some US website recommended that they should be set 40 inches from the wall - a bit difficult in my case.
I also find - like so many other speakers - that the tweeter is very directional and for best results one's ears must be in-line (or slightly off-axis) with the tweeters. The tweeters are off-set from the mid-line of the box as you know; the tweeters should be on the 'inside'.
The owner of LV recommends some very esoteric Kondo cable and valve amps - but also Class A amps such as the Sugden range. My Quad 306s seem to drive them fine (they are Class A before the 'current-dumping stage' takes over.)
So glad you like them. Do you find speaker cables make a difference?
BW
R