New amp for Vandersteen 2CE

As a McCormack fan, I would normally say go with McC.
But, as you have the Adcoms, why not upgrade them at MusicalDesign and see if you like them?
I had the Adcom 555 running while my DNA-1 was being upgraded by SMc. When the DNA came back, I was very pleased, but I have to say that old 555 really held its' ground for a 35 year old machine. As you say, the Adcom is kind of rough around the edges, so when I asked Musical Design about the upgrades, he said it gave it more smoothness to the midrange.
For the 555, it was quoted around $300, for the 565, probably a little more. But, that's alot less than the $1800 I paid to upgrade the DNA-1.
You haven't mentioned your interconnects. Those can make a big difference in the midrange, as well.

Thanks, really appreciate the McC and Adcom comparison.  Since the 565 are a pair, upgrading does start to add up, and the cost is pretty similar to a DNA 0.5.

I build my own interconnects using teflon or foamed PE shielded cable.

Once owned a pair of 2CE's and should have kept them. I had the beige socks which looked nice... also had the Sound Anchor stands which are a must. All the amps you mentioned are good amps and I've heard them all except the Odyssey. I wouldn't spend the money to upgrade your 565's; no doubt the Musical Concept mods will improve them... they're good mods. The fact as you mentioned you don't need the power and as you describe them is accurate with the Adcom amps. Adcom's were great bang for the buck and yes Musical Concept or Design mods were very popular back then. 

I I haven't heard the odyssey amps but they get great press and a lot of people hear throw them out so hopefully they really own them or have spent time listening to them.

Between Adcom, McCormack DNA 0.5 and the Pass A5 it's definitely the Pass with you speakers and what you are looking for. If the DNA 0.5 was a Deluxe I'd still go for the Pass. If you needed the more flexible amp and was set on the DNA 0.5 look for a Deluxe as it is a much better amp than the standard one. 

The Pass Aleph 5 is a very nice amp and on many speakers it's not the ideal amp but it will work nicely on your Vandies. It is a little toaster as you probably already know. If you don't like it, it will be an easy sell.

the Sonos has a great user interface but a poor quality DAC

I second the Odyssey.  Although I no longer own Vandys, I had a pair of 1Cs when I first bought my Odyssey Audio Stratos HT3 (with cap upgrade).  This is a very good amplifer with smooth, detailed highs that helped take some of the edge off the Vandersteen metal dome tweeter in the 1C, which I found somewhat etched and grainy.  Look around for reviews on the Odyssey amps, I think you will get the impression they are worth a try.  Sold direct with a 30 day return option.