As a former Pronto owner who moved to a Harmony Remote at Christmas, I would also have to recommend the Harmony. I've got a 555 and it's been great so far.
It's no where near as powerful as the Pronto but it can still do everything I want it to, and setting up the activities etc on it is so simple anyone could do it whereas programming the Pronto was somewhat of a labour of love!!
525 lights up blue... 555 lights up orange. Other than that, the 555 has two additional buttons, 'sound' and 'picture'. when pressed, they effectively take you to a new page of controls, so all of the buttons on the controller can be assigned commands relating to either sound of picture.
For example, Im my activity called Watch TV, the volume buttons control the tv volume, the channel buttons control my pvr etc etc. when I press the picture button, all the buttons are assigned to controls for the picture adjustment, so I can adjust the tvs brightness etc etc. and tinker with the outputs of the pvr etc.
For some of my activities using my amp, if I press the Sound button all the buttons are assigned for tinkering with my amps settings. Press the sound button again when I'm done and the controller is back to controlling the dvd player/amp volume etc etc.
Valve