I have the Janus that I upgraded to Signature a few months ago. I think it is fantastic. It is the best preamp and phono stage I have ever heard.
I bought the unit used. It was already at Aesthetix as the previous owner was getting it checked out and ready to sell as he moved up to the Jupiter series. Aesthetix fully upgraded the unit and included a new 3 year warrenty.
I highly recommend the upgrade. The people there are great to work with as well. It will take a while as I understand a lot of Saturn series owners are doing the upgrade.