The bearings in handles make a solid difference. The ones with bushing suffer from wear by accumulated detritus, if the knob shaft is made of duralumin. Brass-shafted knobs tolerate bushing way better than duralumin ones.
So, if you have duralumin knob shafts, bearings are a must-have.
Several companies don't do that, since using bushing-duralumin shafts is cheaper.
