"...are these guys actually having some legitimate products or services?"

rsync.net is built entirely on supermicro head units and, until a few years ago, their JBODs.

Then they got greedy and tried to do the old "certified drives" bullshit with their JBODs and that was the end of that ... now we use the celestica JBODs we source from IX systems.

Head units are still supermicro, though. Fingers crossed ...