Rich,
You don't live where there's much construction, right?
I have a dedicated in the stereo (Kenwood/Garmin) unit in two of our vehicles. They're wrong about exits and freak out at highway intersections that changed due to construction. In Kenwood/Garmin's deal, updates aren't free.
They also won't route around traffic even though both have the FM sub carrier receiver for traffic and will display it.
Heck, I reported a road open that Google showed closed for years. And another that had been closed (and huge poles driven through the road surface as bollards) for years.
In Waze, I can do this...
To get Garmin's data fixed with my free labor meant finding an obscure web page on their website that would only work with a desktop browser. I finally did it out of annoyance weeks after I realized the Garmins were routing around the best road to go someplace constantly.
For my free labor reporting their data screwup, I got... Nothing. And paid $70 for each head unit to upgrade their data when they finally fixed their upstream data months later.
You and I both agree that Google and their know-everything data collection may not be the best thing ever for the world, for various reasons, but it's hard to beat them on mapping and road conditions. Garmin's cute little $100 gadgets don't come close.
They could... If they'd strike a low speed cellular data deal for them and include it in the price, like the early Kindles did and still have...
Another area the Garmin simply can't compete is in finding business names. Waze does it with a combination of searches. It has its own data, and at the bottom of the search screen you can choose Google, Yahoo, and various others. And it does the query in real time. New business? No problem. It'll probably be in there. It'll grab the address and route you right to it.
The Garmins only get used on long road trips on Interstates and even then only if the phone is getting used for something else or doesn't have coverage.
The only data that all GPS data collection companies still seem reluctant to add is bridge and overpass heights. Rand McNally has a co-branded Magellan (I think) that has them --ostensibly for big rigs and RVs -- and it gets horrible reviews. Their iPad app is even worse.
The feature request and comment thread to get Google to add bridge heights, and a way to limit routes by vehicle height, is years old and many pages long. They aren't going to do it. You're still better off with a paper Commercial Vehicle Atlas, and those are running upward of $100 and don't include changes for construction.
I wouldn't put the Garmin hardware units in the "better" category. I'd put them in the "good enough as a backup when cellular data fails" category.
I moved the iPhone's to TMobile last year. Arguably either the third or fourth worst carrier for coverage in the entire country. I was interested to see how they did on the OSH trip this year. Was prepared with paper and the Garmin as backup but wanted to see how Waze worked out on a long route I already knew.
We had data coverage throughout the trip adequate for something like Waze from Denver to OSH with the notable exceptions being passing through Lincoln, NE until Omaha and over the bridge into Iowa, and the entire State of Iowa, where apparently the roaming agreement is so poor that it was throttled until it croaked. Everywhere else the roaming agreements were "fine" but not stellar speeds. Plenty for an App like Waze, though, and checking in on email once in a while.
This is on their $100 for two lines Unlimited voice, text, and data plan, which has been refreshing compared to Verizon's pricing. Flat rate and it works very well considering TMo's coverage struggles outside of metro areas.
I am aside about being "back" on a truly unlimited plan... I used over 3GB of data last month on just my phone. iPad used some more. I don't even care when Foreflight warns that I'm updating map data over cellular anymore. Haha. Go for it! (I'd love a checkbox in the settings that says "don't warn me, my data plan is unlimited, so I don't care", but then again I'd also love it if it'd just update itself without having to launch it and fiddle with it.
) I had an early Verizon unlimited plan many years ago and kicked myself numerous times for dropping it. Nice to be back to data pricing sanity. $600 a year per person for unlimited isn't too awful, really. I've figured out ways (Waze? Heh) that I could make it marginally cheaper by playing games with pre-paid plans or watching the meter closely, but $50/mo post-paid per person for the two of us, for unlimited data and everything else is really hard to beat for the brain dead simplicity.
Anyway, morphed into a cell phone data post, but Waze and others really are better than Garmin units at this point in the game, as long as you have that cell data connection. And I'm on a crappy carrier and had no problems anywhere other than Iowa with mine.