@runwell I got my 160S in December, directly replacing my '75SE.
The '75SE is a sweetheart of an amp. I love the way it looks and I've used it with Von Schweikert VR4SR and Vandersteen 5A speakers (and a couple others for short times).
In comparison, the 160S was like cleaning the sonic lens. Much more immediate, making the 75SE sound sluggish by comparison. Dynamics are improved, leading and trailing edges of notes are more defined and natural sounding. The soundstage is both larger and more precisely focused, and there is more information. The 160S seems to have a lower noise floor.
The 160S, cold, with no hours on the clock, bested the 75SE in all categories with the possible exception of a relaxed quality in the high frequencies that could have just been imparted by the new tubes in the 160S. I've got nearly 1000 hours on the 160S now and it's been absolutely fantastic.
All that said, I haven't been able to bring myself to list the 75SE for sale. I have it in a closet now, I like knowing that it's there if I want it. It's one of those products I could really see kicking myself for getting rid of in the future.
Let me rephrase when I said "the 160S blows the 75SE out of the water." I expected the 160S to be better. Hell, I expected it to be a lot better than the 75SE. The difference was more than I was expecting.
With the 160S, I have the impression that I'm hearing more texture and detail in everything, everything is more filled in on the surface and the image is more solid/dense overall.