I have seen Gordie Brown more times than any other entertainer in Las Vegas and I really enjoy his show. I first saw him in 2004 and through the years have gone to see the changes in impersonations.
He has changed his act some and he is depending less on George Bush and Bill Clinton for laughs but they're still in his act. And, I'm sure they'll still be drawing laughs in the years to come.
Brown has updated some of his material including an attempt to do some rap to appeal to a younger crowd. The problem is, a younger crowd is generally not buying tickets for his show. The show hits very much those of middle age and older (you define middle age--I won't.) If you read the reviews on Yelp, people will often rate the show good or bad depending on their age. That's not a bad thing--it's merely what people like.
I'm sure I'll be heading back to see Gordie in another two years. It was almost exactly two years since I saw him before last night and I enjoyed myself. And, I still laughed at k-nock, k-nock! If you don't understand that, go see his show!