My wife and I have seen many of the Cirque shows. While we haven't seen the Beatles show, I would say that all the shows we've seen would have looked great from anywhere in the theater or big-top. If you want to get picked on, sit close to the front. If you want a big overview, try to get seats as centered as you can and toward the back. I've always enjoyed sitting centered in an upper level since you can see the aerial stuff without getting a stiff neck.
Have fun, I want to see that show too, it looks pretty cool. I've heard they are incorporating personal recordings that John Lennon did while writing songs in his home. The program I saw showed everyone being "nice" to Yoko. I guess she needs to sign off on stuff.
