I do a large number of miles on my TDR250 which still has the standard 320mm disc up front with a blue spot caliper from an R6 and a mastercylinder from a Yamaha WR125, the feel and stopping power is awesome and two fingers are more than enough to put you over the bars if you wished.
The standard master cylinder and the blue spot still make a good brake but the effort and the feel is pants.
Hope this explains my thinking.
If we were a little nearer, you would be more than welcome to have a spin on the TDR and see what can be achieved with a caliper or master cylinder change.
Pete.