Hi Chris,
Each has its own merit. I like the SD40 because of its portability and of course it's realistic drums/percussion sounds.
What I love with the PA1000 is its completeness,everything are there, vocal effects/harmonizer, powerful built-in speakers, songbook and deep in customization.Sounds are great too with minimal tweaking. What I love with E-A7 is its weight, live sounding, usable styles, easy to use,expandable,and lots of real time controls like sliders, knobs. It is cheap too.