My boyfriend and I went on the High Roller this past Thursday evening around 10pm. We used a groupon and were able to redeem it easily at guest services. There wasn't a wait at all when we went and we actually had an observation pod to ourselves. The pod next to us was the happy hour pod and it was PACKED with people - they looked like they could barely move. The groupon price is $69 which is basically the price of two night tickets - it's only a deal if you get the happy hour all-you-can-drink option ($109 for two), but beware that you might be packed in like sardines.
There are two benches inside to sit down and you get a 360 degree view through the observation pod windows. It was pretty cool to see the strip all lit up from 550 feet up (if you get lucky you can see the bellagio water fountain show) and there's music playing but the ride is incredibly slow. The entire experience is 30-45 minutes and once you get to the top, coming down is pretty uneventful. There are some screens with a really corny narrator who gives you information about the ride - I wish there was an option to turn him off. We ended up going again on Saturday with my cousins who had free passes. I honestly wouldn't go again unless I was going for free but it's definitely something to experience.