It looks like he nail it, both could handle what you need, it is a cosmetic choice. Which one look better to you? If those are in your price range its more about looks. The MX-900 is has more macros that can be programmed but in my house I have 2 MX-850's becouse I liked the feel better. I have client that like the feel and look of the MX-900. It's all what you like.


Thanks
J.Todd