different seats will give you a different viewing experiance.
If you sit in the back, you'll take in more of the overall show, but if you sit towards the front, you will notice more of the minute details of the show.
Either way, there are not bad seats in the house. Some off to the extreme sides don't have the best sight lines ( and they are only sold day of show anyways ). Just some seats are more prefered, thus more expensive.