They've done some live vocals if they're not too processed - the new album has more natural vocals than ever before so I foresee more live vocals this tour. A-Chan in particular has a great voice.
And they are quite a few notches above Kendrick on the 'legend' ladder of music history.
Disagree wholeheartedly - what makes MCZ ten times more attractive to see live than other idol groups is their energy and stamina and balls out-ness on the stage and it would not come across half as well if that didn't include singing their asses off even after doing acrobatics around the stadium for two hours. It's impressive and charming.
And here's a solid example of how decent they are vocally when not running around like mad (still 20 songs deep in the set list). http://vid48.com/watch_video.php?v=YH33B5R8SHY9
Of course Perfume's appeal is different - the perfection of the moves, the club atmosphere, it's like the Daft Punk pyramid - whether the sound is live or not is not that important.
Perfume lives always have like a new stage gimmick. Their lives always pioneers some sort of innovation with stuff like projection mapping and unique set designs.