Comment by sgt

Fortunately I don't spend a lot of time in either of these but what I did notice was just the UI being more difficult - so UI friction makes a big difference, especially across thousands of users in a government department.

Also lots of minor bugs, like font kerning looked weird, missing features (one cannot expect it to keep up with MS on this, they've got full time highly paid developers working on MS Office every single day), various incompatibilities... some bizarre crashes.