We now have 4 850's in use and several new and used waiting for the original 4 to kick the bucket. We were also using the mx-200 until a few years ago. It is a very nice few button remote. Have a couple used ones and several brand new just sitting in a drawer now.
Oh, if anyone is having issues with the buttons, check out the keypad repair kit. It works extremely well.[Link: p1repair.com]