My post on Unison remains one of the most popular things on this site. (The FF7 Trilogy remain my most popular posts, the ROM Collection Browser post is far and away the most popular hit on the site this month, and a number of people seem confused, as I was, by Netflix's reorganization of Doctor Who -- but Unison's still way up there.)
Well, I rebuilt my computer a few months ago, and I've opted not to go back to Unison. The main reason is that I don't just have Windows/Linux/OSX machines in the house now -- I've got a phone and a tablet both running Android now, and I'd very much like to be able to sync to them, too.
(Yes, okay, so Android is also Linux; good observation, gold star. It is technically possible to run Unison on Android. It is also, as far as I can discern, as big a pain in the ass as you would expect.)
I've decided to take a crack at ownCloud, and set my overworked G4 Mac Mini up as a server. It was a quick, easy setup, and a lot less fiddly than Unison (though it took a little bit of fucking around on the command line to enable SSL), but it's got its tradeoffs -- oddly, near as I can tell the desktop client can only set directories to sync, not individual files, while the Android client can only set individual files to sync, not entire directories.
And speaking of syncing with the Android app, it took me a day to figure out how to get it to sync in the first damn place. The sync toggle is under the system Settings menu, not, for some reason, anywhere in the app's interface, and it turns out that in order to set a file to sync, you have to upload or download it first, and then tap it in the ownCloud browser, and then there's a "Keep file up to date" checkbox. It's not exactly what you'd call discoverable, and the closest thing I can find to documentation is a damn YouTube video. (Can we talk for a minute about tutorials that are only available as videos? For my money, that trend fucking sucks. I mean, videos are great for some things, like showing you how to take apart a piece of equipment, or shave, or otherwise do something that's easier to watch than read about -- but much of the time, step-by-step instructions with the occasional illustration is a far superior method of walking someone through how to do a thing.)
So, not quite perfect. And there are some other pitfalls -- the filebrowser in the Android app can't seem to access the directory with my World of Goo save to sync it, SNESoid save files use a different extension than desktop SNES9X...plenty of rough edges that aren't actually ownCloud's fault but the fault of developers who didn't consider that users would want to sync save files across multiple systems. (It looks like you might be able to sync a file under a different name on the Android client than on the server; I'll look into that but I'm also thinking of switching from SNESoid to SNES9X EX on my phone and EX+ on my tablet. So far it looks like it's a lot more flexible than SNESoid, and while EX+ is too burly for my phone, EX runs all right once I turn off graphics filters, set scaling to integer-only, and turn on the GPU Sync Hack. Save states aren't compatible between versions, but of course save RAM is. As for World of Goo...maybe I can whip something up with symlinks or something; I'll look into it.)
And it's a pity there's no way to set up an automated wireless sync with my PSP.