I've had my Darbee for 2 weeks and have only watched it on my 70" Sharp.
Either BRD rips of HBO True Blood, and several sports -> golf, football, etc.
IMO this box is a no-brainer. For me, set it at 50 ( Green or Yellow ) and forget about it.
HD-cable has plenty enough flaws, so whatever additional flaws the Darbee might introduce, are far outweighed by its contrast & sharpening benefits, IMO.
I FINALLY got around to hooking up on my JVC RS65 shooting on my 120" Silverstar ( eventually to be replaced with 11' wide scope HiPower or DNP 2.3 )
Watching LOTR-ROTK first thing I did was reduce the JVC e-Shift setting from 3 to 2 -> too much film grain at 3.
Also for the helluvit, set the JVC sharpening and noise reduction to 0.
I set Darbee to 40-50-60 and used either Green or Yellow mode, Red is just too aggressive.
Let's just say the Darbee knocked my socks off.
Turning Darbee off, made the image now appear blurry in comparison, though obviously it was stellar before the Darbee was introduced.
Again, no brainer, set it at 40-45-50 and fuggetaboutit !
Disclaimer: I freely admit I am no Videophile.