adjustable end points.. limits to travel of linkage
adjustable curves of action.... to adjust for limited traction... current limiters.. brake power. a few even has a form of anti-lock brakes.
most mid-level radios offer this stuff.
I do miss my duel rate steering button on the handle like the Futaba 3PK had..
for me.. it was set at 60 percent for racing.. but in a wreck,stuck to the wall ... my little finger could press the duel rate button.. and steering goes to 100 percent,, but only for the time I have the button pressed.
except for this one issue.. I like my Futaba 4PLS.
I have been running Tekin ESC for about 12 years now.
RS gen 1 and RX8 in tenth scale dirt.... the RS also in carpet racing.