I have only knowledge of Tom Tom 1 and whilst it is good it is far from 100%
Despite signing up to map updates it still hasnt got roundabouts installed 2 or more years ago - It reminds me to 'Keep Right' when all I would be doing is going left into a parking layby. At other times it doesnt advise me to keep right when I really nned to - It has led me into Tescos car parks more than once and finally the main road veers sharply left, I need to effectively go straight on but the voice and indicator are strangly silent.
my 2 pennorth
bnut