I was cleaning out my 360 hard drive yesterday and saw an option I'd not seen before. (Console settings> Display>Display reference levels.)

Heres the MS page on it,

http://support.microsoft.com/kb/906663?sd=xbox

It was apparently upped in May last year, but what exactly does it do? I think it displays more colours on screen but its really hard to gauge exactly what it is, that it is doing.

On Standard I get the normal display, on intermediate (after some TV contrast settings) I get seemingly more colour depth, and Enhanced is too dark (contrast goes ape basically).

Exactly what is the best option and has anyone else even seen this?

Edit
How do you set the best TV display? It drives me mad that MS don't have a calibration screen on the 36 dashboard. Right this very minute I'm googling THX tests that maybe I could use.