It only took ~15 minutes to get a basic setup working and looks to replace 8 remotes. A little more experimentation was required to improve usability (for some reason, the backup command on a sky remote was not mapped to a physical button in the Watch TV activity). I've added a sequence to the "menu" button so that the Sky Planner is displayed (rather than two keypresses) and even got it to control my lights (on IR Dimmers).
The only issue I can find so far is that activities assume we don't multitask (e.g. pause a DVD to set something recording on the TV) as "Watch TV" would turn the DVD off. It is possible to control each device indivually if required, so it's not that big a deal... just that it seems clunky in comparison to the activities. This is where the fifth star is lost.
I was tempted by the Harmony One but the 785 is half the price (on Play), has physical colour buttons, and I am not keen on touch screens (hard to find in the dark).