New McIntosh amp build quality

In terms of the MC 275 VI, I've had a pair mono-blocked for several years, both purchased new. Absolutely flawless construction and glorious performance. No issues with tubes and if rolling is your thing, plenty of alternatives to select from various online tube stores.  If you need to, do a little bit of research to properly match the 275 to the "right" preamp and speakers.  For a preamp, I use the PS Audio BHK tube hybrid. In my opinion, there is no better tube  power amp available near the price point.  While I have no issues with the amp, I would be cautious if purchasing used.  Over many years, I have worked with Audio Classics and never been disappointed.  They test and inspect the used amps and tubes.  In any case, if you're looking for a terrific tube amp, one that can be mono-blocked if you so choose, the 275VI is my top pick. There is a reason why the 275 is consistently on Stereophile's Class A list.  Cheers!

Build quality of the electronic internals is superb on the latest C2600. Beautiful. 

However they have skimped on the chassis. No flush mount screws on the top cover, which I find surprising on a unit of that price. 

I owned a MC275 MKV for a few years and enjoyed my time with it.  Trouble free and great sounding.   I have read that the sound signature of the MKVI has changed and they seem to be readily available on the used market, which would make me want a MKV.