It might just be me, but Yoda seemed awfully grumpy in the prequels. Alright, times were difficult with the rise of the Sith and all those horrible taxation issues, but he just seemed to take things a lot more seriously. Grumpy with Anakin, tetchy with Obi-Wan, he wasnt that much fun to know back in the day, and there was a layer of arrogance that I didnt want to see. Lucas might have called that characterisation, but asides from a few action scenes, he feels a bit impotent in his younger days, unwilling to act until its too late, and I dont really want to see him like that. Basically, hes like a whisky better when hes older.