I have had great experiences with my Cary products. My first Cary products were a used pair of SLM-100's bought from a Cary dealer. When I auditioned the amps, one was blowing fuses. The dealer selling the amps sent both amps back to Cary for service and inspection. After that, I used them for 3 or 4 years with no problems, only replacing the KT-88 tubes once.
I upgraded from the SLM-100's to a used pair of 805C's sold on Audiogon. I have had the 805C's for about 5 years now with no problems whatsoever. I have replaced all the tubes, but only to improve sound, not because they were worn. The people at Cary are always very helpful with their customers whether the products were bought new or used. I have called them seeking advice on everything from the best tubes to associated equipment matching.
With all the good things that I have read about the SLI-80, it's hard to see how you could go wrong.
Jeff