I have a harmony 900 as well. They work off a little differently then URC remotes in terms of macros. The harmony remotes do not permit you to customize true macros. They are "Activity" based remotes. Using your pc, you select the activities you want ("Watch TV", "Watch a Movie" etc.) then assign your components and inputs to the various activities. Then when you press "Watch TV" on the remote, it runs its own macro that turns everything on and switches inputs. When you switch to something else (e.g. "Watch Movie") it turns on what you need for watching a movie and turns off what you don't need.
In short, the harmony remotes are not as customizable but for normal set ups they work very well. I like my 900 more than my URC 850 (which I still use in my bedroom).
If it were my decision, and I didn't need RF, then I would opt for the Harmony One.