I was able to send a bunch of photos with WeTransfer. But when I tried to send some videos, the upload just got slower and slower. I tried letting it run overnight but it never finished uploading. I know the problem is not with my Internet connection as the files were not that large.
The other thing I noticed: It does not seem to be able to resume if you cancel an upload and try to restart it. I can't imagine paying for their service if they can't even get their basic uploads to work.