There is one major feature I wish it had... version comparison. I wrote about it a little bit ago:
"Hey Dropbox, why can't I compare file versions like this?" https://web.eecs.utk.edu/~azh/blog/whycanticomparefileversio...
I do also wish it didn't lock up my entire computer whenever I make a big change to Selective Sync. I talked to a Dropbox PM after my blog post got some traction and he seemed surprised that this is still an issue.