I've never used the MX-850 but my Harmony 880 is great. From what I understand its the same as the 890 minus the RF. It was easy to set up and works wonderfully. I've been through three different TVs, all with different remote configurations, and it worked perfectly. The database online appears to have almost every electronic device that can use a remote. One downside to the remote is that you can't setup real macros. It has the activities, which should do everything you need it to (watch tv, dvd, etc.) Also, once you get used to the button scheme, its pretty simple to use it by touch.
The only other universal remote I've used is that Kameleon, and I didn't like it at all.
