A little late with some input but want to put my two cents worth in.
I have a Good Sam Rand McNally 7725RV and an older model Tom-Tom. The 7725 has a few perks I appreciate: Instant (almost) find for Flying-J and Wal-Mart and a few other things. The ability to develop route on Good Sam web site and transfer to GPS is a neat addition. HOWEVER - there is a ton of other 'stuff' that I will never use and would prefer not to have in the way. I also found it a pretty steep curve to learn how to use the unit. Over all - not really worth my money.
The old Tom-Tom, although I pay for quarterly upgrades, is by far easier to use and will automatically re-route should I decide to divert from the recommended route.
Solution -- I carry both.
NA9E