Yes, basically any $5/month VPS works great for Syncthing.
The only thing I still do use Dropbox for is the share-with-whoever functionality, too. I'd be curious to hear about alternatives for that as well.
(To me it seems pretty orthogonal to syncing folders across machines, though, and I'm fine with and probably prefer using different tools for that. Which I guess I am doing, since I use Syncthing for syncing and Dropbox for sharing.)
The only thing I still do use Dropbox for is the share-with-whoever functionality, too. I'd be curious to hear about alternatives for that as well.
(To me it seems pretty orthogonal to syncing folders across machines, though, and I'm fine with and probably prefer using different tools for that. Which I guess I am doing, since I use Syncthing for syncing and Dropbox for sharing.)