I too use DEVONthink, but I really wish they would upgrade the software. Because I want to keep my databases on my iOS devices, DEVONthink is really the best alternative out there. I can do a direct sync without having to put any information in the cloud.
I also use a Synology NAS, and Iâm going to investigate whether there is another tool that will allow me to sync information across devices using the NAS. My only other requirement is that it must do more than just manage files, otherwise Iâll use Finder to do that. I like the auto-classify feature of DT. I wish Omni would come up with something in this space.