What will you mostly be using it for Anthony?They all work pretty well, but some are better suited for walking, geocaching, the car etc....
We had a Tom Tom before the Navman - and find the new one to be way better.It could be that the newer Tom Toms are better, but ours (now in the missus' car) takes forever to find a satellite and has a less intuitive interface, it's "fiddly". That may well be different with the newer models, but I'd put some thought into how easy it is to do things like key a destination in whilst you're going along.