Probably one of my posts you are referring to.
I installed my hydro with 4 wheel drums before doing the D44 and disc swap.
I felt much safer even before the disc swap.
Other than magnifying any existing problems I dont see any downfalls.
Yes is requires very little pedal force, probably comparable to the gas pedal. Tool a little getting used to.
I always kept my drum system in good working order with no pulling before the booster, so it didn't pull when I added the booster.
Yes you will still have the fade problem when braking a lot since the drums cant get rid of the heat like disks do, but as far as cold braking power, no problem locking up all 4 at 50pmh if necessary.