My husband and I just went and it was in the top 5 nights of my life! I can't even put into words how amazing it was. The 12 year old girl within me came out in full force for sure!
The tickets were a bit pricey but SO worth it!! The theater isn't that big, so even though we were pretty close to the back, I felt like we were closer to the front (the picture attached is from our seats and not zoomed in, so you can kind of get the idea).
The drinks were very pricey, but that's to be expected in Vegas. If you drink mixed drinks I recommend getting the triple shot in the souvenir cup. It's $24 for the first and then $19 for refills. It's the best bang for your buck, especially if you're going to have a couple. And the cups are actually really nice!
So, if you're a Backstreet Boys fan do not hesitate. Just do it! You will not regret it!