The MX-900 can handle up to 40 devices with 40 pages per device. Plus the Before/After feature when programing macros. I also like the in hand feel of the remote over the MX-700/800/850. I have small hands with short stubby fingers and it's a bit cumbersome when your trying to reach the buttons on the upper portion of the 700/800/850. I also think the 900/950 looks cooler then the 700/800/850.

I will say that I really miss the Gem Stone buttons on the 700/800 remotes. I wish they would bring those back.