I would say the loudness of a crowd doesn't specify how good a crowd is. Without videos that's hard to tell anyway, since how loud a crowd really is depends on a lot of things, the size of the crowd, the venue and how loud it is in the mix.
Foreign shows like Brazil, South Africa are/seem a lot better because people don't get to see the band very often and get extra nuts because of that fact.
I have both been to european and american shows and I have to admit the america crowds are not as "lame" as I expected them to be. People sing loud everywhere. When you look at older shows people went a lot more crazy back then. The shows were heavier, people have grown up since the old days, and more are busy taking photos and videos now.
Does anyone really listen to a certain DSP because the crowd is great? I don't. I listen to the shows that have special songs, great performances or just because I've been to the show. They are a professional band, the crowd doesn't add much to their actual performance.