If you want a good feel for the advancements in Navigation systems in the last 10 years, you should check out my piece Looking for a Nav system from 2008. The article went through my key issues that lead to my recommendation of the TomTom's in those days.
TL;DR: Today, I just think you should use whatever is best integrated with your phone or what gives you the best traffic or routes in your most frequent driving areas.
Running through the items from the article:
The Nav system should (mostly) trust you
In the original article, I stated "believe" you, but I think trust is the real issue. If I drive in a different direction, the unit should figure there may have been a good reason for it and give some priority (at least a tie breaker) to the human driver.
MapShare updating technology
I thought this was going to be a helpful tech at the time, and it is, but it's now supplanted by much better connected algorithms for navigation. Not only does your Nav system believe you, but if you drive over a road that the device doesn't know about often enough, there's a good chance it'll show up in a future update.
- Better pricing on map updates
Not much better pricing than free, or at least included with your device. Take your pick of how to pay: subscription for "pro" software, free for Apple's defaults, or with your data in the case of everyone else. But, you generally won't be paying a fee unless you are using pro software.
- Better Management Software No need for this any longer. Once your mapping system locates you, as long as you're online, you have the maps you need. There are some systems designed to allow you to choose the areas to cache, but generally that's not necessary except for specialized systems for activities like hiking.
- IQ Routing
Thanks to the connected nature, this is a non-issue. Everyone has segment-based timing these days, automatically reported back; usually while you drive.
- Advanced Lane Guidance
Table stakes again.
There are still some difficulties:
- mounting brackets are still a problem
Unless you have a navigation system that coordinates with your car (Apple's CarPlay and Google's equivalent, Android Auto), you're probably struggling with some difficult to handle device to hold your phone.
Now that everyone's driving is being monitored by their navigation system, some amount of private information that was previously unavailable is now available to bad actors. You may trust your phone provider and OS manufacturer (although that may be a bad idea in some cases), you have to watch any App that has access to your location outside of when the App is running.
- Cell coverage == navigability
It's getting better, but in many cases, if you lose your cell coverage, your nav system not only loses its ability to get real-time traffic data, but you may be stranded without a map.
Tune in in 2028, and maybe I'll update this topic again!