I have set up an OwnCloud instance on my server and I have noticed that it was extremely hard to get the master revision to work properly (which means: allowing it to install apps), and the last version they have for download also lacks some polish here and there (but wasn't too hard to set up). IMHO: the basics work good (file synchronization and such) but if you want a bit more than the vanilla package (like tell it where your music is, rather than it scanning everything in your data-directory indiscriminately) it might be a bit of a challenge. :)
Not to be a cheapskate, but I wouldn't buy a >$30 book for it though. You have to buy the Android app if you want file synchronization on your phone. But that's 80 cents or so.