In a nutshell -- most is the same, some has changed - Big difference is the user interface.
If in W10 and needing Acrobat there is really no practical choice --- ya gotta move into "DC".
I have been using W10 for a while and installed Acrobat DC. I tried it for a couple of months but today I de-installed DC and went back to Acrobat XI Pro which works fine with W10 - the interface and overall performance is much better. I will not go back to DC and don't recommend it - to me it is clearly a step backwards from XI Pro.
For what it's worth I also preferred the UI in XI, but I have warmed to DC over time. For accessibility work DC has some definite advantages, for example the built-in ability to add the PDF/UA ID. As CtDave points out, we will all have to move to DC and/or its successors eventually.
a 'C' student
Agreed on the accessibility advantages but overall I think Adobe missed on DC - I gave it a good run and feel that I am wasting too much time on the clunky UI - XI Pro works fine on W10 so I can wait - I own the license for DC and look forward to DC's successors. I would be interested to know why my comments require moderator approval.