First and foremost, I was fortunate enough to score free tickets to this show. However, my wife and I decided that it is definitely good enough to pay for, and we will be treating both sets of parents to the show next time they come for a visit. GB does cater to the baby boomer audience, but there was definitely humor and impressions that the Gen Xers would find funny.
Don't go to the show expecting an over the top stage show, as the theater is small (but very very nice) and the stage is pretty minimal with Gordie and his band. This show is definitely a hit for the value, and if you are visiting from out of town, make a night out of the show and dinner at one of the many good downtown restaurants.
My wife and I have seen a lot of the less expensive shows in town, and this one definitely is at the top for us. It is non-stop, and it is very entertaining. If you got the time, check it out!