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.
Ketron SD90, Korg Pa1000,TC Helicon Play Electric, Fender Sonoran Guitar, vArranger, Bose L1 Compact, Aiwa Exos-9