An interesting article on TrustRadius shows end users reviewing these two document management systems (or Electronic Content Management Solutions).
TrustRadius is where business software users share their insights through in-depth reviews and networking. Their goal is to help users make better product selection, implementation, and usage decisions. No vendors are allowed to comment on the site, so these are unbiased user experiences and views.
Overall, M-Files is rated as a better solution and is a clear winner with its usability.
SharePoint has been around for much longer, so their user base is larger. However, many users are finding the older system more complex whereas newer technology is much more user-friendly. M-Files provides tools to manage everything on your own, without having to rely on IT. You can manage documents, information and processes without having to consult a user manual. It's intuitive, accessible from all of the programs you use and it just works.
Users agree. Utilizing a newer system like M-Files is better for your whole organisation as it is designed for how businesses operate today.