Hi Jack,
Glad you like the mat. Either are good and an improvement over stock.
As for the DPS, all the owners I know, which is a few, use one. We all heard the difference it brought. The wall warts provided are just ok, can be noisy in some systems. Some on here, like yourself, try other devices and have good luck. How they compare to a DPS I'm not sure. The DPS was there, it was WTL approved, and that was that, as they say.
I and others did laugh, and were a bit puzzled, in the WTL review by Art Dudley, where he finds the DPS added nothing. The DPS, like many things, needs run in and needs good support. It's also a reminder that not every review gets it completely right.