Compare Latency Communication between Earthmate IOS, Google Maps and Waze. Whats the difference?

I am returning to Garmin after a 5 year Absence.  I was a Garmin fan for 15 years. I'm trying to catchup on the Garmin products capabilities. I understand that the Earth mate is basically an extension of Garmins inReach product.  Is there any lag time between the satellite and the device when it comes to sudden directional changes.  One of the benefits I originally enjoyed with Gamin in the 2000s was the stored maps on the hardware.  These maps were very helpful when navigating through dense cities  when compared with Google Maps that would have most of its data in the cloud.  The signal latency would cause me to loose my signal and cause havoc on my journey.   As I am considering inReach and Earthmate in 2020, Do I need to worry about the latency communicate between my ipad, Earthmade and inReach service?  I'm a world traveler and rely on my Navigation gear to guide me in the USA, Japan, Philippines, Singapore and beyond.  I had the opportunity to use the Wave on my phone in some remote places and the service was superior to Google Maps when i made some comparisons.    I believe the ability to have a locally stored Map and waypoints on a device make a big difference.  Does anybody have additional insight regarding this topic?  How does Earthmate compare to Google Map and Waze? Thank you. 

Regards, 

Herman Bongco

World Traveler
Honolulu, Hawaii
Tokyo, Japan