Looking forward to giving the PC4 a spin. I've been looking for controller (for soft-synths) that also could back me up in the event of a computer failure. My PC3X is great, but throw that thing in a flight case and it is pretty hard to move around. The PC4's weight is right where I want it to be, but I'll want to play it to be sure the weight for action trade-off is acceptable for me. I don't love the DC jack for power (I always have a backup adapter for power, but an AC power connector feels more sturdy, in general), but that wouldn't prevent me from buying a PC4.
I know this is like Pepsi vs. Coke for many people, but I like the wheels on top of the keyboard to reduce the width. The Forte 7 is attractive to me for that reason (although I do like having all 88). We'll see how the action feels on the PC4 before I make a final decision.
Thanks for the manual - that helps answer a lot of questions.
Great job, Kurzweil!