Those are comparable in terms of output but they sound fairly different.
Duncan Distortion:
-quite strong for output
-upper mid emphasis
-has some "quack" to it which although helps it sound modern sometimes makes it feel "forced"
-tight in the lows
Gibson 500T:
-very strong output
-more natural sounding than the Distortion, fairly open/clear
-can be a bit loose in the lows if your guitar has a lot of resonance in some lower frequencies