I saw Def Leppard last year in Eastlake, OH and they were very good. I also saw them many times in the 80's/90's. The only problem was that Joe Elliot was not hitting the high notes. The cool thing (I guess) is that the rest of the band would 'help' him hit the highs. Wasn't perfect, but effective. Vivian Campbell was excellent and Phil Collen actually surprised me. The last time I saw him, he sucked BAD. I guess 10 plus years of practice does a body good.
I was contemplating seeing Journey/Def Leppard in September but my main worry was the new singer for Journey. As 'Nancyboy' as Steve Perry is/was, he is the defining sound of Journey. He has a very unique voice that would seem to be hard to copy and there would be no 'middle ground'....an immitator would either be 'good' or 'very bad' IMO.
Oh yeah....as far as how they sound vs. their studio sound of the Hysteria/Euphoria era, they pretty much nail it down. I was really surprised by how well they sounded overall.