Fred, I don’t have experience with Kudos. But what I know is that when I replaced my B&W cm5’s (rear ported loudspeakers) by SBLs, the frequency response was much better. No strange booms anymore on certain frequencies. The replay was just as it is. Also, no more ringing tones on higher frequencies when listening to piano music. They can sound a little dry, but compared to other loudspeakers I have heared a great relief.
An extra benefit of the SBL’s of course is that they are quite small (but still large compared to your Iota Alphas) and go against the wall. I liked the Alphas as well by the way - they have things in common to the SBL’s.