The Yamaha CP-5 digital piano provides a nice piano sound, however less detailed/muddy in low octaves compared to Roland FP-7F’s one. The touch is also less realistic/pleasant. Strings sounds are far more impressive.
The Kawai MP10 sounds like a real piano (details and texture of sound, notably in lower octaves, and great expressivity), contrary to other digital pianos that remind we are playing samples. The sound seems however somewhat distant (despite a presence setting) and panned a little high, overall more processed. The touch is close to FP-7F’s one. Strings sounds are also great (even better than on the CP-5).
The Korg SV1 brings a less interesting piano (reminds the one from the M-50) and the touch isn’t realistic. It however provides impressive strings sounds (and synthetic ones/pads), great organs as usual, and interesting electric piano sounds (not static thanks to onboard effects that alter the samples).
The RD-300NX seems finally interesting and features a great additional church organ (not found in FP-7F, however included in the RD-700NX). Despite feeling very lite/unrealistic, the touch remains correct, as well as the overall sounding.
Finally the RD-700NX touch is a little heavier than on the FP-7F, gradded, and keys sides feature a wood texture/color (the top is however less realistic than on the FP-7F). It includes the same SuperNatural Concert model as on the FP-7F and RD-300NX, plus a Studio model (tighter and not really necessary) and a Brillant model (very interesting, emphasizes the feeling of modeling).