The main downside of Tresorit is that it does not support syncing symlinks. It also does not have LAN sync like Dropbox does. Tresorit does have E2E encryption, which is great. Only the enterprise version of Dropbox has E2E encryption.
That is unfortunate for both symlinks and for a lack of LAN sync. Not having the ability to deal with anything I throw at it does add risk that the sync isn't true, but outside of the OS I don't use symlinks. LAN sync would save data transfers over slower links but with E2E is this isn't too surprising that it's centralised.
Thanks for sharing, I didn't find this option when I looked. This might be a winner for my uses.