The IR database is a great tool that isn't present in the MX850. However, if you don't see yourself changing your current components for years and don't foresee adding multiple components, the MX850 will work fine. Having 10 commands/components on screen is nice and is something that you don't get with the newer remotes.

The MX780 is a nice remote but the screen is miniscule. The MX850 is a tank as well (aside from the RF chip that breaks off which it sounds like you won't be using). If you have been happy with the MX700, I would stay with it or step up to the MX980 which looks better, fits better in most hands, programs better, etc.