A bit late to this thread, but I just picked up a Bob's Devices Sky 20 and am thoroughly impressed with it. Quite remarkable how a tiny box like that can produce such a huge increase in resolution - without the usual SUT artifacts like high frequency rolloff, loss of detail or hum. And this is after owning a whole raft of highly-rated Japanese SUTs. There's a lot of hype in this hobby (business?) but Bob's Devices transformers are the real thing.
Bobs Device SKY 20 or A23 (Denon) SUT for my Charisma 103 cart
I will be adding a Step Up device to my system soon. It's an Amadeus table, Charisma 103, which has ruby cantilever, but nearly identical specs to a standard Denon 103. These will feed my Croft phono integrated driving Harbeth P3's. I'm leaning toward the SKY 20, but does anyone have any experience here. I'm a little surprised these units haven't been compared anywhere that I can find. Art Dudley did a write up on the Sky, but in the article he made reference only to A23 Homage SUT. Cheers -Don