I did. Using PA2v2 with my iPhone 4 via LOD gave a cleaner sound compared to the headphone jack because its pure. Pairing it with the PA2v2, RE262's were comfortable to me. They're much more dynamic/livelier sounding, fuller and lush, and extreme ends of both bass and treble are better extended. There is just more impact and wow when you use them with an amp.
Without an amp, it sounds okay - just not up to the ratings and glorious reviews that headfi has given them. These really do benefit from an amp.
No idea if using other more powerful sources would change the results.
Btw, the Re262's have another plug that you plug into for a balanced sound. Unbalanced out of HP out, one side does not have sound. Why is it that when I use the same unbalanced plug into the PA2v2 amp that it gives me both sounds?