As i dont want to miss anything i run my T2 reasonable high sens wise and as low disc usually about 4,running it with such a high disc @51 would knock out gold and certainly most of the silver hammered coins that i am after,cannot see any real advantage by cranking up the discrimination so high,infact i would say you stand the chance of missing some very good targets.
As i understand it a slight boost can occur at about 50 this observation has been noticed by folks from the very start,but of course its not like switching on a turbo mode,i doubt that most folks would even notice it,but they would notice the drop off in targets,so for me i will carry on using my method of using small amount of discrimination and high sensitivity but not so the machine runs un-stable.
I find that when using a large coil say like my SEF 12x10 or 15x12 on open clean ground i can use between 2-4 disc,80-85sens,and either 1 or 2+ on the audio,freq shift 7,and Energizer batteries,deep enough for me,if i want to go deeper with a VLF then i would use my Nexus or TDI Pro but only on the right sites.