Tour operators are very nice. The sunset at the summit is great.
Now some realistic check. You will need to consider following: of the 7-8 hours tour, only about 2 hours maximum is on the tour itself, and the rest 5 hours are spent on transportation. The issue with our tour is that the weather is just so-so. We saw the sunset under heavily clouded sky and then hardly any stars. My assessment is that you are spending quite some money, time and risk of altitude sickness to take this tour. If weather is not that good - you would better rebook under much better weather. Otherwise, you may feel a little bit disappointment.