LFF,
I haven't heard them. In general though, I find that a modern piano usually is out of balance in a baroque orchestra or ensemble. The added volume and powerful dynamics compete too much with the rest of the instruments. Remember, the modern concert grand is made to hold its own as a solo instrument against the full orchestra as demonstrated so well with the music of say, Rachmaninoff. The baroque orchestra had fewer instruments and also the instruments did not generate the same volume as the modern instruments. For example, baroque cellos lacked the endpin which gives the modern cello extra sonority by making the floor an extra soundboard, and the internal construction of the other string instruments also produced a softer sound. Most modern baroque violins and cellos have been altered to produce a fuller sound. I also wonder just how and where the piano would be placed upon the stage, would the case be open or closed, would it be at stage front, and would it be a full concert sized grand or a smaller model?
I am not the type of person who insists on historic performance, so I would be open to a good performance if there is one which incorporates a piano. I just don't see how it will work for continuo, and I suspect it might have too much color for my personal taste.