I hadn't heard of Adam Lambert singing with Queen but I just watched some videos of it and it just wasn't that good at all. While Adam is a very talented person it would be hard if not impossible for anybody to ever live up to arguably the greatest vocalist of all time.
The problem with Queen is while they are all incredibly talented musicians Freddie was the show when it came to live. I was born in the wrong time so never got to see them but have watched their live concerts so many times... In fact, when I was a kid me and my best mate would act out Live at Wembley.... And I was so jealous of the kids in The Miracle video!