While I myself don't have a Phenom 9850BE I do have a Zalman CNPS9700 on a Q6600 OCed to 3GHz. During the winter my CPU never gets above 50c and idle its 30c. And during summer when its over 100F here my CPU never goes above 55c.
Its a great cooler and looks great.
But I have heard the Zerotherm is quite good.
But from the test I could find the Zalman 9700 if you run it at high fan speed it comes in at just under the Thermalright Ultra 120 by a few degress which is quite good considering it has a smaller fan. And from what I can find the TR Ultra 120 is the best of all of them.