Here's an opinion from a Music Store owner......
I like two models I sell for the musician who would like 88 hammer action keys, arranger functions, light enough to take to a gig, and sounds that would please any ear listening.
First, the Roland KF90. Great sounds, styles, 16 track sequencer,built in speakers, vocal harmonizer, notation on the touch screen plus lyrics, and a price that is much less then it's KR brother.
The Korg SP500, for about 1/2 the price, is similar but without speakers, vocal harmonizer, disk drive, user style programming, but a good value and it satisfies your need for a good piano feel and sound.
Yamaha will be coming out with a new keyboard in a few months called the Pf1000 which I posted some info about a week ago. It will feature Clavinova features but without as high a price. It will be about the same price as the KF90. I don't have all the info on it yet, but I don't know about the vocal harmonizer yet.
Just my two cents worth!
George Kaye
Kaye's music Scene
Reseda, California