piano samples for garageband 3

The Garageband 3 grand piano is decent, but some of the notes sound tinny. Sometimes there is an unevenness and I can't tell whether it is my touch or the piano sample. I am looking for an upgrade for not too much money. I found iPiano, which comes with 5 piano samples including Steinway and Bosendorfer, but I only saw a garageband 2 version. Jampack 4 comes with harpischord and a piano which is reportedly good, but I am not really interested in all the orchestral loops. What is the best, affordable solution for sounding more like I am playing in a recital hall rather than in my living room, through the iMac?