No, the username needs "@bingodisk.com" to work at all.
I did some testing with bingodisk's WebDAV performance (just with the Finder) and found it to be very slow. I have some information from the bingodisk parent company's tech support (Joyent). I asked them about the speed of small file creation which appears to take at least a second or two, and here was their response:
Indeed creating a file is a little slow. These is on top of a zfs file system so creating the meta data is what is taking some time. So uploading a single 1G file is way faster then uploading 1000 1k files.
This is frustrating because the OF sync's blue bar moves step by step about 3/4 of the way across, then rapidly finishes with the failed sync and the bad gateway message. It
almost works.
Any other ideas?