I'm gonna say something controversial but the CGI Yoda is just as good as the puppet from ESB... perhaps better.
http://www.youtube.com/watch?v=3KH1GOFUCHk
Unlike with almost every other CGI element of the PT the animators slaved over Yoda as can be seen in the production videos. They were working on it for along time before they even showed/told Lucas because they were so scared of screwing it up. They did research frame by frame into how Frank Oz's hand moved inside the head to mimic it exactly with the CGI muscles. They wanted it to look like the puppet but with subtle facial movements not possible with a physical puppet. They even copied the exact way puppet Yoda's rubber ears woblled when he moved. I believe Adywan is approaching ESB:R Yoda from a similar perspective with very subtle CGI ehancements (Like he did in the Cantina).
I would consider CGI Yoda to be the second best performance in the PT, just behind Ian McDiarmid.
Yoda's leaping around at the end of AOTC is another matter. Again as can be seen in the production videos the animators had prepared a subtle and convincing way for Yoda to move but Lucas took one look and said no he should spring around like a Frog, as can be seen in this video...