Agreed - in my 101 the rear brakes do nothing around 99% of the time - the propositioning valve doesn't even begin to open until there's around 300Kg in the back, which isn't often.  Front brakes pull it up very well - the new discs, doubly so, but even with the drums up front, it stopped pretty well when they were adjusted properly.
I did try and adjust the proportioning valve once to bring in the rears sooner - with, um, shall we say 'interesting' results - requiring a change of undies when I got home. [biggrin]
Had a passenger while doing this - Mick Marsh - here's a link to his post about his thoughts on the brake test - 
https://www.aulro.com/afvb/101-forwa...ml#post2329858 [biggrin]
Should be post 540 if I've done that right...