Hm, too bad.
But I wonder if copying the content of the stick, leaving out /etc/udev/rules.d/* and /home/<user>/* to hdd/ssd isn't pretty much the same then copying an ISO? What's the difference? Is there a difference? If there isn't, then all that what's left ist installing grub to mbr. Done. I really wonder whether the installer couldn't be extended to do so for the benefit of heaving an always up-to-date stick with install capability?
Anyway, my installation to the stick didn't survive a reboot. I yesterday installed, d-u_ed to the stick, installed some packages including flashplugin-nonfree, watched TV/videostreams the whole evening/night while posting here in the forum. I changed back from systemd to sysvinit-core which might have caused the problems for today's reboot (no X, systemd-service didn't find something like "user@service" or so; the fsck showed errors all over the place, too big blocks. I still haven't tested the stick whether or not he is dead now, I'll see).
So, in theory this works fine, in practice it did, too. Until something went wrong ...