It just does not work
Whilst this service seems like a great facility in practice it does not work. I signed up so I could move my Flickr to Google Photos. First I tried the cloud sync....did not work, task kept failing after partial completion. Support suggested to break down to smaller tasks. I tried that grouping albums by letter and creating tasks. Didn't work, transfers failed and I ended up with multiple albums. Contacted support. Told to wait and try again, cloud quotas etc. Requested refund, told not possible over 30 days etc.