Very true. The pain point seems to be largely the database merges; it's possible to roll your own db while using iCloud mainly as a key/value store for synching user preferences and status between devices. This is particularly useful if you support more than just apple devices...

Edit: regarding offline sync (which I didn't address) something like AFIncremental store is a good example of how a local persistent store can be maintained in tandem with the online store.

(But, as you say, non- trivial and hard to get right.)