I have it working on all my 3 devices, Mac,iPad and iPhone all updated to the recent software update. My only problem is when i have a new photo it takes hours sometimes days for all to sync. I have strong Internet connection. Thanks.
I just got back from Maui (3 days ago) and we took a lot of pictures while on vacation. I turned off the iCloud for photos as the Internet at the condo we rented was terribly slow. As soon as we got back I turned iCloud (for photos) back on and I noticed my MBP and iPad updately very, but my iPhone didn't. In fact, it was several hours later when I went to bed and it still wasn't updated. The next morning it did finally catch up. I also have fast internet.