never flown a DC10/md11, but their biggest competitor, the L-1011 (a.k.a Lockheed TriStar) was said to be the better aircraft, especially during the approach phase.
* Larger, more efficient rudder
Because Douglas opted for straight duct on the no2 engine, height restrictions prevented them to design a better rudder (read: taller)
* More efficient placement of the no1 and 3 engines
The s-duct on the TriStar allows for a lower CoG, so the wing engines could be mounted farther away from the fuselage. hence turbulent air from the fuselage will pass by the engine inlets instead of going thru them.
* Direct lift control (DLC)
The L-1011 incorporated a pitch-smoothing flight control system within it's
spoilers or speed brakes. State-of-art at that time...
These are just some small tidbits. But keep in mind the DC-10 outsold the L-1011 by nearly a 4/1 ratio, so Douglas managed to design one of the finest aircrafts ever, no doubt

Just want to credit my source
http://flytristar.tripod.com/page/feature.htmlGreat page with lots of info regarding the TriStar

Edit: Hope CraigL doesn't read this, or else he'll post 500 reasons why the DC10 gave the TriStar a whipping during the 70's