Have said I was going to ditch rsync.net as my backup provider, I’ve decided to change my mind. The eventually got back to me today having finally fixed my problem a whole month after I reported it, and a full 14 days after they last were in touch.
However, my problem was very specific, very random, hard to reproduce, and not a major problem, just a small feature that wasn’t working. They did resolve it in the end, and every message I received was intelligent.
So, I’ve decided to stay put. I’m still keen to use S3 for media storage, but rsync.net are a better option for incremental, automated, nightly backups.