It is clear to see that Nextcloud is not totally new software, but has been developed around the free ownCloud. In terms of file storage and file sharing, there are basically no differences between the two applications.
Key differences come when you look at the add-on and security features: on the one hand, ownCloud’s licensing policy ensures that certain components such as full text search, workflow management, or branding are only available to paid Enterprise customers. Nextcloud users do not have these limitations, as only support and update services cost extra. On the other hand, the latest features such as audio and video telephony suggest that the Nextcloud team will focus increasingly on extending the functionality of the app and developing it into a complex online collaboration platform. In the meantime, ownCloud wants to focus on optimising security features, however, Nextcloud does seem to be one step ahead with features like default brute-force protection.
As a relatively new software, Nextcloud still has the typical beginners’ problems: the website, originally in German, is also available in English and is lacking user instructions and has a very limited online manual. Updates are also not as smooth as with ownCloud.