I've used Dropbox since the beginning, and Nextcloud for the last few years. Nextcloud client seems to use %10 of the memory of Dropbox on my machines. I'm now in the process of switching to SyncThing. The advantage of Syncthing over Nextcloud, is you can used it centralized or decentralized (without a server), I dont need to manage SSL certs and I dont have to poke holes in my firewall. Syncthing client also uses very little memory (a bit more then Nextcloud, but hey Syncthing is both a client and a server). Each of these services have their own strengths, so it depends on the features you want.
The greatest power of Syncthing I've found is that once you get two devices to handshake, you're done.
Laptop, meet phone Id, phone, meet laptop Id. Laptop, meet desktop, desktop meet laptop. Oh I've got my server, server meet desktop meet laptop and vice versa.
Want some files to be available on all devices at once? Put it in the Bank Cannister folder which you've set as active for all devices.
Want to drop airdroid or plugging in your phone's internal storage to transfer media files to/from the phone? Setup phone<->laptop<->desktop folder named PhoneMusic and tell the syncthing app to store the contents of that file in the same directory as your already existing music root.
Want off-site backups but too cheap to pay for backblaze like me? Backup to Blu-ray, local external drive, and sync to off-site location (my dad's PC or DO droplet).
And when I say sync, I mean setup the syncing folders then let it background P2P sync on its own time. Eventual consistency might as well be instant for all but 1% of the time where you look for the file then see it written to the 'local' drive before your eyes.
I had a lousy experience setting syncthing up for the first time, but then a really pleasant experience using it. I would recommend it as a decent sync option
For those on Windows, I recommend the SyncTrayzor Syncthing wrapper. Made the thought of getting Syncthing initially configured a lot less daunting and made getting off Dropbox much easier.
