Good question.
I have mixed impressions of owncloud so far depending on what area of the product you are using.
The good parts: Contact and calendering managament. Just works. Integrates nicely with Android, Thunderbird, etc. Not very good synching back to Google though. I don't really care about that, but now you know.
The not so good parts: I tried running it on my NAS, because that would be the storage-backend for the file-sync service anyway. I quickly discovered that the code is not near efficient enough to be deployed on underpowered devices like this. It needs optimization, or to be put on proper hardware. I chose the latter and redeployed.
On my NAS, with enough data getting synched across clients could take days. So don't even think about putting this on a Raspberry Pi or something silly like that.
The worse: Using owncloud's files-module as a drop-in Dropbox replacement, you will be surprised by how well supported all kinds of platforms are. If you treat it as a Dropbox replacement though, you will encounter issues.
I tried putting my code/project/build-folders under owncloud and hack away, much like I've done with Dropbox. Even with a limited amount of clients, you will quickly encounter at least some bugs. The most annoying thing I encountered was probably getting conflicts when only one of the clients had updated the file.
The client updated the file, called back to owncloud with the changes, and then got a response back that this update cannot be done cleanly.
It then proceeded to the code/build/project files involved in the conflict and rename the local and the "server"-version to $file.conflict345678543 & $file.conflict1234567 or something to that effect. Needless to say that broke my code, my build and needed to be cleaned up.
If you think that sounds annoying, imagine it happening several times during a 30 minute coding session.
So yeah. The owncloud file-service currently suffers and cannot be treated as a drop-in replacement for Dropbox. Hopefully it will get there, but outside coding, I haven't experienced anything like that and it seems to chug along just fine. With a high CPU-usage though.
So yeah. There are good, not so good and directly bad things about it. If it fits your use-case is up to you.
Funnily enough I have both Baikal and BitTorrent Sync running on a Raspberry Pi (model B/512) and it is handling it surprisingly well, I even use it as a destination backup server for some VPS's and local computers (using duplicity). I just wish the Pi had more RAM as BTSync is a bit of a memory (and CPU) hog when you start to hae a lot of files involved, it is under strain. My compromise has been to tar a lot of folders I rarely access to cut down the number of individual files it needs to track, not ideal. I was thinking of buying one of the Intel Next Unit of Computing I think it is called, which is more powerful but still power effecient enough to be left on 24/7.
