I know that the Universal remotes subject has been covered many a time but I'll kindly ask once more. My dad is looking to get a Universal remote and we (I've) decided to get a Harmony because they have them at BB and since my brother works there, the remotes come to about half off after the employee discount. So of the 676, 680, and 880, what are the "meaningful" differences between the three? Simplicity is of the utmost importance as it will be for my mother and father. I will be programming the remote, but ease of setup would be nice as well.

My father's components are as follows:

Denon 884 AVR
Denon 5 disc CD/DVD player
Hitachi RPTV
Scientific Atlanta cable box

So other than the drop-dead sexy looks of the 880, what else justifies its price over the other remotes?