I've been told that the call quality on the TomTom 720 or 730 and similar models is not the best compared with dedicated bluetooth units. I don't have the TomTom app yet. A GO 720/730 will cost me more but I don't mind if it performs better.
The other thing I could do is get a TomTom One instead + a Parrot Minikit which I can get for free but that would mean 3 devices to charge if needed.
I appreciate any suggestions