"I also have one failed (shorted) DP2X that you need to know the reason. I sent this to a customer to replace a DP5X in a Kato RS-2. He fried it and sent me the engine back to figure it out." - one of our customers.
The board layout of the DP2X allows it to seat so that the screw that holds the Kato board to the motor fits up between the large components and shorts the small ones in the middle. The problem can be solved with a piece of tape over the screw (the screw has to stay in to keep the LED's lined up with the light pipe). You may want to print a warning somewhere to watch for this. It's OK in Atlas engines since they use a plastic snap to hold the board in. I'm returning this decoder for replacement and so you can see where the screw shorted it out