Kennymacc,
I have never heard either but know the Salon II well, currently use JBL 4367s and my last speakers were Revel 228be. My comments below are just keyboard warrior stuff…
Anyway I have seen you state you really like the Salons (so do I) and I would guess you would be pretty disappointed with the Volti longterm. Stereophile has measurements of both the Rival and Razz and both look pretty bad with large suck outs in the mids and lots of comb filtering. Going to make for a very bright speaker next to the Salons.
You would gain dynamics (a lot of dynamics probably) but have to fight the odd tonal balance. I would guess you would miss the bass extension too. However the build quality is great and they use good drivers but I could not deal with the frequency response.
I see you also asking about the JBL K2S9900 and I think I would stick with the JBL line if you want to try horns. The newer JBLs (M2, 4367, SCL-1) are all joint projects between Harman and JBL. You get the JBL drivers with Harman philosophy on tonal balance. The issue with the JBL (short of the M2) is they all lack bass extention and need subs IMO.
The Unison looks interesting