I'm sure you'll have a great time! I saw them last year for the first time. It was a very long show (3 - 3.5 hours). The first half is somewhat slow paced. It is narrated and there are only glimpses of their lights, lasers, effects, etc. The second half of the show is where they play all of their more energetic and popular stuff and the place goes crazy with the fire, lasers, lights, etc.
I'm just mentioning this because I didn't know what to expect when I went. I was a little disappointed during the first half because of the pace and lack of a full-blown light show. I thought it was going to end about 1.5 hrs in and I was kinda glad; but, then they kicked it in to full gear and rocked out for another 1.5 hours or so. Prepare for a long show and it will definately end with a bang.
I haven't decided if I'm going this year yet. They're coming to my town on Dec 20th. I'll have to wait until it gets a little closer since I don't know how busy I'll be at that time.