Hi
I'm back Screen glitch at boot on iMac 2009
with news after 17.2 update
install with USB2 is very long
also the integrity check
a total of 4 hours or so
this time I don't any glitching problem on the screen after install (nvidia ge-force 9400) - just a quick one when shutting down
that's great - i'm going to keep zorin for a while - after a good experience with Mint (less than an hour to install)
I do have the same bluetooth menu issue not showing - i have to resize the window to eventually make my device appear in the list...
all hardware seems to be working fine 
iMac10.1
Intel® Core™2 Duo CPU E7600 @ 3.06GHz × 2
8Go RAM