Photos iCloud sync is extremely slow and looks like its throttled server side

I think it's just like that - it's always been like that for me with average up and download rates not much better than dial-up. It's why I don't use it for photos because, at my age, I won't live long enough for it to finish uploading.

I don't put photos in the cloud and I don't use the Photos app. I synch them to my iDevices with Finder via USB. I only really use iCloud for synching apps like Calendar and Contacts because it's no use to me for anything else. I tried to use it to synch docs I'd need when out and about but it's no good for that either because when I needed anything I'd find that my iPad had offloaded all the iCloud content and if I had no internet (a common occurrence for me) then I couldn't get to them. There's also no way to just download everything. I certainly wouldn't pay for it.