The biggest difference between NT and DM is the Low Pressure Regulator.
DM has an LPR while NT doesn't. When it comes to practice, DM is a softer gun than NT, it kicks less, it's more gentle on brittle paint but it's less air efficient. NT is smaller, lighter, more efficient but has more kick and is a little picky with paint.
As eblemis wrote, the biggest difference is the LPR.
The DM is gentlest on paint/smoothest. The NT is most efficient. Generally I'd presume most like the NT ergonomics better.
DMs are generally worth more than NTs, mainly because the NT line has developed a (partly undeserved) reputation for breaking paint.
The biggest difference between NT10 and NT11 is the operating pressure which is ~20 PSI less on the NT11 than on the NT10.
Specific changes: Milling, emblems, spool, spacer rod, bolt, efficiency kit and solenoid manifoil.