Hi Matt, I think both Akai & Yamaha's models are nice with some differences in design aesthetic. I like EWI 4000's built-in analog synthesizer and its touch sensors are fun to play with. (Plus it runs on AA batteries, pretty convenient). WX5, to me, is a really fine pick-it-up-and-play digital instrument. It takes little getting-to-know-you time and I thought the layouts of octave keys are very interesting designs. Interestingly, Yamaha's WX5 is exhibited in MOMA in New York....which surprised me a little. I guess that I was expecting to see EWI 1000?
JK