From what I remember from my NAPA days, Midland is equal to Bendix. Air dryer is good to have. Back in the Army days(92-94) most of the 5 tons didnt have any air dryer and had that oily goop in most of the valves and just about everywhere we didnt want it to be. On the flip side, my '94 Kornbinder has one and I've been driving it for over 6 yrs with only 1 air related problem(governer leaked air). That's 80k miles of driving