I've got the same problems with my 2015 Silverado 2500HD - the ETA is always WAAAYYYYY off, among other irritating things. Got an e-mail into the sales manager at the dealer I bought this from so we'll see where it goes from here.

 

I purchased the GM - NEXT GENERATION INFOTAINMENT SYSTEM MAP 2 years ago (at a whopping 180$ Cdn) in order to have the maps updated and with the hopes that it would be better...not a chance. It's terrible!! The worst GPS system I've seen. BTW...those updates should be free once you paid for it. Like Garmin and TomTom, they at least provide you with a free lifetime update...GM doesn't...I'm certainly not about to pay another 180$ to find out that it still sucks.

 

2009 silverado really good navigation, 2015 yukon denali agree with 2015 vehicle owners, horrible piece of garbage problems to numerous to list, 2017 yukon denali much better but updates to hwy system that have been updated for over 2 years now by garman and google maps still not updated in GM navigation, 2018 gmc sierra navigation works well so far however it has now been about 5 years since other map programs have updated (expample) green bay wisconsins new ramp roundabout updated road system,,, however GM has still apparently decided there is no real need to update there road system.