My experience has been very good with these new Clavinovas. I really like the CVP 503/505 and 509 because of their piano sounds--they are pretty amazing. The CVP 501 too is pretty good as well. The only thing I can tell you is to try them all and play them for a while. Selecting the right one takes time. It is like selecting the right pair of shoes, you have to try them on to find the best fit for you.
This might help: have a look at my Clavinova CVP 500 series articles. There is also a recording I made of the CVP 503/505's piano that are in those articles. It will give you a good idea of what the piano sounds like.
* CVP 501 Review
* CVP 503 Review
* CVP 505 Review
A review on the CVP 509 will be online shortly.