iPhone's Dropbox upload does work well in my experience and (almost) the same as Android.

2 problems I'm aware of:
1) For large amounts of photos it is slow since it has to go up to the Dropbox cloud and back (not sure if the iPhone Dropbox app supports LAN syncing as a source but it still has to upload it either way before any other machines can see the files)

2) If the phone goes to sleep, it stops uploading (on Wifi at least) so you have to keep waking it up. iPhone takes more control over apps keeping it awake, screen on etc than Android.