Thank you for your input, Steve.
You know Casio is selling the PX100, an 88-key hammer action keyboard that weighs less than 30lbs. and costs $400. That light and with 88 hammer action keys. It doesn't feel like a real piano, but it's pretty good.
I don't think I would want the weight and throw of piano keys on an arranger keyboard.
But there is room for improvement with Yamaha. The PSR3000 was an improvement over the previous models. I enjoy playing the PSR3000 more simply because of the better key feel. Ideally, I would like the keys to be a little heavier feeling.
The advantage of an arranger keyboard over a midi controller is that the buttons are ergonomically placed in just the right place for the functions that are needed - especially the style variation buttons and the registration and voice buttons.
I think that if someone were trying to change styles on a controller that had programmable buttons, a lot of mistakes would be made pressing the wrong buttons by accident. I think there would be a lot of frustration about not having the buttons where you want them, lighting up how you want them to light up. You would have the advantage of the better keyboard bed and playing around with voices made from huge samples, but you would not have the buttons and the display made solely for an arranger.
Beakybird