I was looking at the Starbo, but bottled getting it as its fairly new and a bit unknown to me.
I ended up with the 510 xl europe, which is good, but I find it sticks to major roads (not ideal in London).
A friend pointed out a little fact which is so true... when your taking directions from your tom tom, have a look round if you pull up to a busy set of lights or something... 50% will be following a tom tom too!!!
Might be worth getting a different make of sat nav, so it varies the selected routes...
having said that, yes it sometimes goes the long way round on the main roads, but it gets you there in the end.
Cant fault mine tbh