I just bought a 2007 LS460. The voice commands work great (for the most part). Sometimes other noise, etc. aren't recognized (especially voicing numbers for the phone to dial...it often adds numbers).
The only voice command I couldn't get to work, was "CD Changer". But that may be because you have to have a CD in the changer, for it to recognize the command. Not sure.
I love having all the controls on the steering wheel. I can even tell the climate control what temperature to set....for example, "68 degrees". Pretty cool.