The Harmony One is my second Harmony, and I like it a lot.
I love how the display lights up when you move it slightly, so there's not button to fumble for in the dark of my HT room. I also like the fact that you don't have to replace batteries.
What I don't like is that it it rarely turns off (or on) all my equipment at the same time. Actually, it's almost always the ceiling-mounted projector, and I realize that if it were in the rack with the other equipment, I probably wouldn't be having this problem.
try standing back a bit when I'm turning everything on or off, but even then it rarely works. I have to hit 'help' and go through the menu (is you A/V processor on? Is you digital cable box on? Is your projector on?) to get it to work.
I still like it, but this part is bothersome.