Received my Flirc today, set it up for my Windows XBMC Box and my older Logitech Harmony 656 remote and it's working great!
I set up my Logitech Harmony 656 remote as ASUS O!Play HD2 remote, ran Flirc software to program the keys, loaded up XBMC and its running great, no lag when scrolling through the menus, doesn't miss a button press or pause and then jump ahead like I have read other posters here complain about.
I did grab an old remote I had that had a few other keys that the Asus O!Play remote didn't have and programmed them in with the learn IR option in the Logitech Harmony software, like the 0 to 9 number keys, record button and the guide button, info etc etc.
I did not adjust any delay options in the Logitech Harmony software for the remote, I left it at the default settings.
I can now put that big old keyboard away and use just the one remote.