Although I enjoy playing both keyboard and piano, I'd have to definitely vote for the piano.

While a keyboard provides you lots of fun with rhythms, accompaniements, different sounds, portability, I personally feel that I'd be able to express myself better on the piano.

Although my roland does a very good job in emulating the grand piano sound, I still love the natural accoustic sound and feel that the piano provides. This gives me the impression that I'm more "in control".
I was never able to add all the variations I wanted on a keyboard because of the key feel.

Maybe because I just come from a piano background

Claude