the pedal is only a little heavier than with the drums but was already running a tandem cylinder. not as light as i'd expect it to be with a booster but the pedal feel's pretty good

had no trouble with the rear drums and have had a very reputable brake shop look over the whole set up, the're opinion is the balance should stay right with this upgrade.
if you're running 12's now you'll need to get some 13's as the 12's don't fit over the caliper

i run 13x5.5" and haven't got a problem and i know a ute with 15x6" that needed the lip rolled and the guard pumped marginally. offsets the big player in it, but you should be right with most 13x5.5" s that don't have a huge offset