I don't know about any of the other celebrity voices; I sampled them and there almost all pretty crappy), but I tried the John Cleese voice and it seemed buggy.I installed it last night and just to see it in action, had it navigate me to work today. It gave me the correct turns and everything, but I would hear things like "Four hundr... turn right ahead" or "three hund.. after.. turn right ahead". Is it always like that, or is it just me?