Both very good guns, two very different platforms with a spool bolt closed system and an open bolt poppet marker.
If you can get a chance to shoot both or similar guns that try it.
As far as reliability/efficiency goes they are both very similar indeed many new players (or lazy players) prefer the reliability of the PE brand as you can get them covered in paint and mud, chuck them in your bag and pull them out in a year and they will still work, where's as some prefer the soft feel of shot the DM line provides.
If I couldn't try either and was just going on advice is take the DM.