[magsafe]

iCloud offers one benefit over this, which is iCloud allows record-level syncing (for SQLite databases using CoreData).

Dropbox is file-level syncing. So if you have a database app managing many records in tables, Dropbox will sync the entire database when even a single record changes. iCloud would only sync the record(s) than changed.

[aaronbrethorst]

iCloud offers a theoretical benefit but is a bit hosed today when it comes to record-level syncing: http://noidentityapps.com/blog/?p=905