You can import the codes from the MX-850 (particularly learned codes), but not the layout, so overall it's likely going to be faster just to program everything again from scratch with new database codes, new clean learns, and new hex imports where needed.

The newer URC remotes are much more flexible in how you can program them (mixing and matching multiple database codes in a single device, for example, and more sophisticated macros), and as soon as you figure out the vastly different CCP programming style, ALMOST as fast to program as an MX-850.

Just remember to follow prior advice and ensure that where you buy from will supply you with the software. Any help you need you can find from searching or asking in the forums.