I have the Harmony 550 and in a handful of minutes connected to my laptop I was able to swap out functions for the new Blu-Ray player and TV I purchased recently. For awhile there I had it set up to control my components not just in the living room, but the bedroom as well. It could control my living room home theater system(minus the bluetooth PS3) and then I could take it to the bedroom where it could control my TV, HTiB, DVD-recorder and cable box and it worked perfectly. My 9 year old girl can use it with ease and if it gets out of sequence, she is perfectly capable of using the remotes help function to get everything back where it's supposed to be. Of course, she can also control everything from the individual remotes and does it better than my girlfriend or any visitors that I've had over so that might not be saying much(I'm so proud of her), but it's just so simple to use.
For example:
You want to watch TV...it turns the TV, cable box and for me it turns the receiver on as well. Volume buttons always control the receiver unless I specifically tell it to control the TV. Same with channel and DVR functions(always mapped to the cable box).
You want to watch a DVD...it turns off the cable box, switches inputs on the TV and receiver and again all the pertinent buttons are mapped to the intended device.
I even have a remote controlled fan in the living room and was able to use the learning function to have the Harmony control the fan as well.
I know some people want or need more, but how much more do you need. This remote will control up to 12 devices I believe. Obviously if you have more than you need another remote, but I paid less than a c-note for the Harmony 550 and I've yet to run up against the limits of it's functionality.