we've got the 720 aye. seems good to me. The phone thing is alright, it works, but it can be annoying when you don't want to use it. I've called people before and because the tomtom was in the car it suddenly took over the call
the speed camera thing works I guess, it will sometimes tell you when theres one on the other side of the road pointing the other way.. and I guess you need to pay to get a subcription to keep them updated.
we use the mp3 player on long journeys - we set it to play via the radio thru the car speakers.