[tuacker]

Fair enough, that was me extrapolating from the experience I had so far. I didn't dream to turn on the new iCloud Photo Library so far to see that it'd turn off the iCloud backup part.

1000 Photos might not be 5GB but still every picture gets uploaded, just older ones disregarded once new ones arrive. Now if someone comes home after a day out with a 100 new pictures this puts some stress on your network once while it is updating photo stream (if not done over mobile data) and backing up.

Where some stress is: Complete congestion of the network since 100% of upload is used and at ~50KB/s speed around these parts it'll take forever to even sync 100 Pictures at 1.5-3MB each.