Yes, I enjoy my Uptone ISO Regen. It's provides a subtle change but its by no means a "must have".i see you run a USB isolater before the SU-1? Is that an exception
I guess my broader point is that Jitterbug ---> Eiter --> Singxer --> Holo seems a bit redundant.
If you get your Singxer / Holo you can experiment with removing/introducing components in your USB chain to see if it really makes a difference.
I spent a lot of time trying components in front of the Singxer and gauging their audible benefit.