I've been. I was quite disappointed and I got in free. I'm not sure your 10 year old would get very much from it at all. There are lots of buttons to press and the music room is fun. We did it all in about 90 minutes. You could take longer but that's really because there's loads to read rather than loads to see.
I've just looked up the two people you mention and I see that one isn't British. That means there won't be anything about the Black Eyed Peas at all.

We enjoyed our trip but decided that if we'd paid, we would have felt ripped off. It's possible that having made the trip to Cleveland to the fabulous Rock and Roll Hall of Fame Museum (also probably not suitable for a 10 year old) that we were expecting too much but I don't think so.

But I was there after-hours as a friend of mine was doing a talk on Rock photography so can't claim to have really taken it all in properly.

I found it very dry and quite frankly all a bit boring, some glass cases and buttons to press - looked like a small ante-room in the Science Museum. Not sure a 10 year old would find much fun there.

They were rubbish at organizing the talk too, very amateur - their PC broke down showing the slideshow of the photos during the event, very awkward.