i have a Harmony 525 and it's great! only one problem is that it doesn't have a dock, and it eats through AAA batteries like a ravenous dog (batteries need to be replaced every 3-4 months!). but still you could get one of those, and a bunch of rechargeable batteries and a charger for less than £100. and it DOES have the coloured buttons missing from the Harmony ONE.
Or, what about going for the Harmony 700? I haven't tried it, but it has a charging dock and the coloured buttons too.
One piece of advice i would give - avoid the ones which are TOO touch screen unless you want to spend your life staring at your remote control. Actual buttons are much easier to get used to without having to look at your remote every time you want to do something.
Whatever you decide to do - good luck with your purchase!
525: http://www.logitech.com/index.cfm/remotes/universal_remotes/devices/6011&cl=gb,en
700: http://www.logitech.com/index.cfm/remotes/universal_remotes/devices/6063&cl=gb,en
ONE: http://www.logitech.com/index.cfm/remotes/universal_remotes/devices/3898&cl=gb,en