Spice Girls had something very special and were a great novelty that I enjoyed, but vocally, both Sugababes and Girls Aloud outstrip Spice Girls without a doubt. Also, Spice Girls got very big so quick and went out just as fast as a group, but the two newer bands have both enjoyed longer and steady success without overdoing it. True, they will never be like Spice Girls... the reason being that they're Girls Aloud and Sugababes, end of!!
There's not enough 'oomph' in it which is why I think they've used the speed to try and compensate for it. They had to use all of their voices for the chorus just to get the layered sound his gritty voice has and they still haven't managed it because his had so much more energy and projection,they should have used stronger/more powerful vocals and you never know, it might have been better. It's not bad but it's not classic, it's just like another pop song and they've done their own singles better in the past which says something - they've made a classic mediocre and made their mediocre songs hits.
It doesn't match up to either the Aerosmith or Run DMC version, but I think they did put their own spin on it that makes it fun to listen to. Plus, it's for charity, and you can't lose with that