I don't think it works well on The Voice at all. Their live shows feel rushed.
I don't think we'll see any changes on this sort of scale, to be honest with you. The show's biggest issue of the last few years has been the quality of the contestants. They basically seem obsessed with trying to recreate 2010 (the year of One Direction, Wagner, Katie Waissel - and the biggest ratings they've ever had) but failing. That year was a perfect storm of big characters but also really talented acts, and probably mostly came about by accident. I don't think you can manufacture that like they've tried so hard to do.
Still waiting for what or who the scapegoat for last year's ratings will be. The year before the blame was all (very unfairly) placed on Olly, Caroline and Nick - Olly never got over *that* blunder on the results show, Caroline was the professional she always is, and Nick was actually very witty and insightful.
I love lamp