I had almost the same experience. E-UAE gives me jerky mouse-movement on MacBookAir. I prefer DeluxePaint to PPaint, if on Amiga. I recently bought a Sam440EP and it runs PPaint pseudo-natively, so that took some of the pain away.
(If on a plain Mac you should perhaps try ArtRage. It doesnt pixel well, but the tools give you some feeling of control that reminds of DeluxePaints, smear and blend functions. The results look *much* better than if you'd try to paint in Photoshop!).
Anyway E-UAE is terribly slow, even on decent Macs. If you are just addind Pixels in Zoom-Mode it wont hurt so much.
@Karlos: Are they claiming to Support P6 on a Mac? I havent tried.
