When comparing Tresorit vs OwnCloud, the Slant community recommends OwnCloud for most people. In the question“What are the best cloud storage services?” OwnCloud is ranked 6th while Tresorit is ranked 18th.
Ranked in these QuestionsQuestion Ranking
Pro Client-side encryption
Encryption is performed before content gets uploaded to the cloud.
With clients for Windows, Mac, iOS, Android, Windows Phone, and Blackberry.
Pro Free storage space (get additional space through bonuses)
5 GB, up to 16 GB with bonuses.
Pro Open source software
Pro Allows selective sync
Desktop clients offer sync almost as versatile as dropbox.
Pro You have full control with your data
Only chose a provider or host it on your soho-server.
Con No Telephone Support
Because the software is proprietary, there's no way to review the security practices or really know how the software operates under the hood. As such it can be considered as not safe for sensitive information.
Con Significantly more expensive than just about everything else
Con Not plug and play as Dropbox etc
You may need some help installing it on your web space, though some providers offer free install server.