New uploader is terrible. Yes it may seem cool and flashy but in reality it takes me twice as long to upload photos as before. Not only do I have to manually select which folder I want to upload from (previously it remembered after the first time) but now You also have to upload the photos then wait until they are all done before clicking "done" otherwise there is the risk your pics will get deleted due to errors.
Tonight I tried uploading 11 pictures at one time. With the old setup It would take between 45 seconds to a minute to do this. The new system kept throwing an internet error "something went wrong" halfway through the upload and it refreshed the whole page, (which also deleted all of my entered info on the listing). I was finally able to successfully upload all photos after 8 minutes and only after uploading 3-4 at a time.
After all that said this new system has potential but I feel is not ready to full blown use, learn from issues in the past and make sure it is fully operational for all users softwares and browser choices before making it the only option to use.