Garmin 660 or Laptop gps?

I've been sitting at home researching whether to buy a Garmin unit(660, 680, etc...one with traffic alerts) or a laptop gps program. I have a laptop already. But then I'd have to buy the program and the truck stand, so I guess it'd be the same price either way I go.

Basically, I want:

1. Easy viewing of map display
2. Automatic rerouting, in case I miss a turn(which I am a certified expert at)
3. Voice prompting for turns(text to speech?)
4. Traffic alerts!
5. Shows miles driven, miles to go, etc.


I've seen a friend's Garmin C330 in action. Was simple to use, got the job done, very basic, did everything above except traffic. Map view was very limited though, and I'm thinking a laptop could do this job better?

What do you guys think?