Nice place to visit if you're a Rock-n-roll fan, otherwise, once was enough for me. I think the tickets are way to expensive for what you get. First and foremost it is a museum, then a gift shop. You can't touch anything and some things you can't take pictures of. Unless you want to pay 3 times what a T-shirt is worth, then don't stop at the gift shop.
I went when they were showcasing Beetles memorabilia because I love the Beetles. I found the whole thing quite boring and a drag. The building is beautiful in the outside and a surprising 3 stories on the inside.