I've been tempted to get the Harmony, but I guess I'm still confused on how one remote with a limited number of buttons can replace every other remote. For example, I want to balance the sound levels on my six surround speakers with my Denon A/V system. On their remote, one needs to open up a hidden compartment to get at the sound setup system parameters. Or for the HR20 remote, where are the color buttons?
I can't speak to the Harmony but I have the MX-700. I can control 10 devices on the remote. Each device besides all the "hard" buttons (numbers, FFW, Menu, etc.) there are 4 LCD "pages", 10 functions each so you can learn 40 different codes for each device beyond the hard buttons. And you custom lable each button. I highly doubt you'd fill all that up.
So your A/V system for example, you can learn all those buttons in the hidden compartment to the LCD screen.
And once it's all setup you can then do macros. So on my main remote page if you press the "DVD" button down for 2 seconds it runs a macro that switches the input on the TV and switches the A/V receiver to the proper input and change the device page on the remote to the proper device. I could also set a theater mode on the A/V receiver and turn on the DVD player if I wanted. It's all programmed on the computer so it's point and click macros really. This is the WAF. All she needs to know is push the button for the "activity" she wants to do for 2 seconds and she's all set. Very little training.
You also have several "favorite" screens which you can input stations on. So what I used to do for Sunday Ticket was create one screen for early games and one screen for late games. Say the Bears were on channel 715. I'd then create a favorite that would punch in "7 1 5 enter" and I'd label it "Bears". So if I wanted to see the Bears game I simply hit the button for Bears. I have no idea what channel it's on.
So anyway, back to your original question. When you press DVD, the buttons are for your DVD player. Press Tivo, it's for your Tivo and so forth. So FFW will FFW but for whichever device is active. The Harmony's work pretty much the same.
That's what a Universal Remote does, it really replaces all your remotes.
And if you want to really geek out, go to http://www.remotecentral.com
Yes, there is an entire web site and very active forums dedicated to just remotes.