The Yoda Furbys were terrible about having the latex face rip. The latex they used was crap. The ET Furbys had a thicker rubber face that held up much better, but every ET I had but one was defective . They kept resetting themselves and getting stuck in an infinate loop.
I'm not sure if Frank Oz recorded the voice especially for Yoda Furby but I think he'd almosts have had to. If I'm remembering correctly the Yoda Furby said things that the movie Yoda never did. For example if you held him upside down Yoda would start to become upset and start scolding you. He'd also put you through lightsaber training and would give different instructions depending on what level you are on. I never got very far with that because I basically just bought it because I was collecting Furbys. I probably ended up losing most of the Lightsabers that came with the Yoda Furbys.