I was on safari at the Crater last month / Sept2013. I read so much information here even some saying that it may not be a bad idea to skip the Crater all together. Well although I will say that it did not compare to my visit to the Serengeti I am very happy that we made the visit.
Very tranquil feeling being on the crater floor and beautiful photo ops. We actually saw more predators here than we saw in Tarangire which I did not expect.
Take a look at my blog if you'd like picks and more details of our experience.