Antaniserse: For some reason, my mind still register GOG as the only guaranteed source of DRM-free games nowadays, while the HiB was filed under "pay what you want+charity+soundtracks&goodies" while the DRM-free bonus was never a factor when buying... and, indeed, i just realized that i've never downloaded the stand-alone installers of my previous bundles, and just registered my steam keys.
I have, all of them (that I've bought). I have also registered the Steam keys though, just as secondary backups, or as kind of reminder in my Steam list which HiB Windows games I own.
However, the biggest attraction for me in HiBs so far have been the Android bundles, ie. DRM-free Android games. All the Android games I have ever purchased are from HiBs. From GooglePlay (the Android store) I have only free (adware) games.