Be aware that asking HN is not going to give you anything like an unbiased sample of *nix based developers.
Yeah. IIRC the most popular operating system on HN by far is MacOS X (from past surveys).
I've also asked on reddit r/linux r/programming and r/bsd so I've got a pretty good spread. I'm still getting 2-3 answers per minute so I'll hold of on drawing conclusions until I've closed the survey but it looks pretty well rounded at this point.
"KDE" isn't a Desktop Environment or Window Manager. They're called "Plasma" and "KWin".
@jethro_tell: "Does your dev box have a bandwidth cap?" and "How often have you exceded your bandwidth cap?" appear to be referring to monthly throughput limits (aka "download quota").