I did have issues with mine.
Didn't get any signal for 90% of the time.
Dealer renewed the telematics unit under warranty and its been fine since.
You know there is an annual charge for the service which will probably expire when the warranty goes?? Possibly £120 per year???
You can upgrade the HD Nav - you don't have to go through a $tealer. There's a recent thread on here about it. Cost around £70 total, plus a bit of CD swapping by yourself.