Live performance?

I have a chance to see The Black Keys live, but I've heard varying opinions on how entertaining the show is. I don't want a live performance that's mediocre to cloud my appreciation for the songs. The last band I saw live were The Goo Goo Dolls, and they were alright but just alright. After seeing July Talk, I have new expectations for live performances. I know The Black Keys wouldn't be THAT, but just how uninspired is the performance live?