Yeah, they are definitely different. In fact, OneNote 2016 is much better regarding features, that's for sure. Gote example, as. I learned here - in OneNote 2016 you can lock a section, while in the UWP app you cannot. That's just one example, but I didn't have much time to explore.
When it comes to syncing, I agree those two can have some issues. I always try not to use the two at the same time. When I use the 2016 one, I wait for everything to sync first, then do what I want to do, and then again I wait to be sure that it has finished the syncing. Fortunately, I haven't had any serious issues - I only saw once one if my sections duplicated, and I saw free times hope it created a new section in the notebook called "new section" which I deleted after that.
Hopefully they will solve these things. In theory, OneNote should support several people sharing a same notebook. I working l wouldn't dare to test with my important notes what would happen if few people edited some stuff in it at the same time.
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