On my Galaxy note 4 and & Galaxy S8+ I have TomTom Go and NDS apps along with Sygic and Navitel apps and I prefer all of them over the built in TomTom maps in my Citroen. I think people should remember that there is no perfect solution and nothing can replace common sense. I bought a TomTom 910 around 2006 about £275 upgraded to a 530 then 950 and then moved to using the phone app but at the wrong side of 70 I have no need for the latest and greatest especially as most of the so called upgrades are actually a step backwards. I do like the lifetime map, traffic and speed camera updates though and the 6 inch screen on the 6100 is gorgeous but certainly isn't as responsive as a phone.
Best of all I still carry a map in the car just in case.