One thing for sure is the volume issue would appear to be resolved, my father owned the SP16L and just upgraded to the ARC Ref3, the new tubes should be a gain in performance aswell. I will talk to an owner who has had the 16 and now the 17 for you as soon as I can. My dad was pretty happy with the SP16, it is a great unit for the money, the only issue was again the volume steps, in low level steps it jumped really quick and if you have a sensitive speaker the jumps can be hard to get a volume just right, its either too soft or too loud. Again the SP16 is/was a great unit for the cash.