I like the new Knights, but I was a little torn about the multi-colored armor. I imagine it has to do with name-recognition or some other marketing ideas. I missed out on the old castle sets, but for some reason I have a fair stock of minifigs.
Anyhoo, I agree with most of the posts in that a large majority of the KK2 castle parts are a bit too specialized. They aren't all that great for use in other lego creations. That being said, I do still enjoy KK2. I just wish more of the old castle sets were easier to attain on a limited budget.