who's driven both and which is better?

Currently i am servo-less and am considering retro-fitting a servo, but the hassle involved is swaying me towards an adjustable pedel box which will - as the name suggests - adjust braking front-rear. Which will be worth while if i go rear discs at a later date..

Now my thinking is with a pedel box and no servo the brakes are gonna be the same as they are now? correct? i.e. alot of pedel effot required before anything happens.

The other thing is i'll have to run both rears from one circuit and both fronts off the other, will that still be fine for the mot?