Well I have the digione signature playing for a couple of days and I can say I am impressed. I use the Allo PSU to power the Pi and a sbooster for the DigiOne. It has all the upsides of the DigiOne but on a higher level. In my setup I really liked the clean sound and presentation the DigiOne brought me. The DigiOne signature adds the same but with more realism and a more lively image (more depth and a wider stage). Considering the little difference in price it really is a no-brainer when you are considering a streamer. I replaced a Lumin D1 because it sounded on the same level (digital out) as the DigiOne, but the signature really takes it up a notch.
I am very tempted to take the DigiOne signature to work and compare it to an Auralic Aries G1/G2 and the Lumin U1. I think it might easily perform on the level of the G1.