The Pi's have a ever so slightly more focused sound to me than the Evahs, but nonetheless rich and powerful, and stable tuning like the Evahs, but I've been mashing chords on these Pi's for two months now and they still sound great and STILL have that immediate response I need for something like the Bach Sonata 3 Adagio.

The E in particularly is much better.

I switched back to an Evah Pirazzi gold E string and no whistling