Two completely different keyboardist in style. Rabbit is great with The Who. I especially like his later stuff with them on stage, how he uses more of an organ sound with them....great player!
True, but Rabbit sucked on SHE'S THE BOSS. Come to think of it, so did Chuck.
Chuck has been great with the Stones if he sticks to organ or a real piano. "Fancy Man Blues" shows he can play boogie-woogie with the best of them and some of his organ work (particularly in the eighties) was extremely tasty. The problem is his choice of instruments in concert and how high he is in the mix. The latter is hardly his fault. In truth, some of his keyboard parts sound so much like electric guitars as to be disheartening. I fear without Chuck, the Stones' live sound would not be an improvement. I'm afraid it's one of those situations where you can't have it both ways. We get the plink because you also get Chuck covering as much as you do. If he just played a Hammond B-3 or a concert piano, he'd be a great player but the band's sound would suffer in concert unless Keith and Ronnie were both really on their game night after night.
I ahree with most of the comments above. Rabbit is not really playing bluesy with The Who. I like his work with the Who but it's like comparing apples and oranges to compare him with Chuck.
I also agree that Chuck's work with the Stones is influenced by how well Keith and Ronnie are playing (or not playing and just posing). Something most earlier Stones keyboardists did not have to worry a lot about.