People need to move on from the 850.  It was great in its day but it is way to limiting.  2 main pages, no variables at all.  It is just too basic for the crap gear that is out there today for it to control.  At least stepping up to the 900 and 780 fix those issues and some others.  Variables are incredibly important IMHO.  While the two mentioned have basic variable abilities, it is still incredibly powerful compared to what you would have to do with a 850.  Simple things like powering on a theater with a projector would either result in LONG delays when switching between sources once on, or require two button presses to power the system on.  A 780 or 900 could provide the power on delay for the projector from off, and at the same time have quick input switching between sources with no delay, all way pressing just one button to power it on.  The little things like that make it worth moving on from the 850.