On paper the Rhythmik is better in terms of power and features...However, it is my guess is that the sound difference between both amps are probably the same. 380 watts vs. 250 watts isn't that big of a difference. Roughly a little over +1dB, but the price of the Rhythmik is quite attractive though...
Do you have both of them? I do and i would not hesitate to buy another Rhythmik amp over the PE one for the features it has in it. You don't have to desolder resistors and keep trying until you find the correct one you like. I had this headache with my Dharman clone and the Rhythmik took my headaches away. I can flip the toggle switch to different settings depending on music,movies, etc..