The whole ribbon context thing may--may--make it simpler for a new user to absorb. It amounts to applying the old computer science dictum--there is no problem that can't be solved by adding a layer of indirection. The problem is that it also inserts a layer of navigation for many common operations. Things that used to be just a click away require first moving to the right ribbon, before being able to access the function. One example: switching windows in MS-Word.
What is really bad--many keyboard commands don't work, or at least don't work from all contexts (though some do). For instance in Outlook, I was accustomed to Alt-O to get to today. Very useful, very frequently used. No longer works (at least not the way I expect it to).
Went and returned to default a lot of things that I had set--sort order, group by. It's been so long since I upgraded Office, I can't remember if all versions have done this with upgrades, or just this one..
As far as I can tell, there is no option to make updates to a meeting, save but not send. Yes, I understand the logic behind prompting you to send after making updates, but there ARE use cases for updating, saving and not immediately sending. As far as I can tell, that is now impossible!
Then there is the "To-Do" bar, which might be okay in the Calendar pane, but I really don't need in my email window. So the good news is you can minimize it--the bad news is--it doesn't minimize all the way (or down to a vertical bar a few pixels wide)--it still takes up significant space, and the first few events are displayed horizontally. I think the M$ UX people were high when they designed this one.
Things I like:
- Finally, >9 recently-used files (this one is so overdue it almost seems like M$ doesn't actually deserve any credit here)
- Outlook--meeting updates that don't require a response and re-set all response-tracking