I'm only familiar with the original USB Regen, it definitely changed the sound. Our Tucson Audiophile Group tried out the Audioquest Jitterbug, Uptone Regen and Intona in different homes and the results were system dependent, the Regen and other filters were system dependent, some guys liked what they did, some didn't.
My music server incorporates 3 linear regulated power supplies along with the
Paul Pang Audio Grade V2 USB Card and the USB Regen did not improve the sound.
I used 3 power supplies with the Uptone Audio USB Regen:
1.) stock switching supply
2.) Breeze Audio linear power supply
3.) Poseidon's Voice Katalyst 5v linear regulated power supply
I ended up using the Katalyst, it is the best of the bunch and did the least damage.
So what didn't I like? The Regen smeared the imaging, 3-dimensional images were now spread wider, sometimes speaker to speaker. Points in space became blobs in space. The sound with the Regen was fine, it did no harm but if you have great imaging and depth the filters can kill the magic. I can see why some reviews even mention an increase in bass, I think there is a slight increase in volume. I experimented by tweaking the volume up just a hair when the Regen was removed and a lot of the differences disappeared except for loss of image specificity, all 3 filters made my system sound worse in that area.
In the final analysis we discovered that the cleaner your power supply and electronics, the more harm these devices do. As our members upgraded their power supplies and music servers they ended up selling their filters. Nobody in our group are using the filters anymore.
Hardware with a lot of line noise like laptops, computers (Mac Mini's?) and music servers using the motherboard USB output would probably benefit from the USB Regen but in my experience adding another layer to a tuned system mucks things up. My recommendation is try before you buy.
