Neither of them really "solve" sync. It's still a problem for complex applications but it works for say, 80% of the solutions.<p>Anyways I use both and to me they aren't really competitors. Apple doesn't allow stuff like Dropbox to have tight integration with IOS - the biggest value iCloud provides is stuff like Photo syncing, which they aren't even good at.<p>Funnily enough, what I do is enable iCloud photostream, then store my iPhoto library in Dropbox. The idea is that whenever I take a photo on my iPhone it gets seamlessly synced AND backed up automatically OTA.
I love Dropbox and use it on all my devices. However, I really wish they would implement permissions on shared folders. It's one of the two most requested features that users want, but they still won't implement it [<a href="https://www.dropbox.com/votebox" rel="nofollow">https://www.dropbox.com/votebox</a>].<p>As soon as someone comes along that has integrates as seamlessly on my Windows PC, Linux PC and Android phone AND offers permissions on shared folders I will jump ship.<p>I don't know why, but it actually makes me cross that they aren't listening to their user-base.
Reading these stories is a bit depressing. Coding since 5? Solving problems with Finder even Apple couldn't figure out? Is this really the level of technical accumen needed to make it in the startup world?