We use the Garmin RV660LMT and overall has been good to us so far. Also, I like the speed read out as it is more convenient to read than speedometer.
I do use Google Maps to compare and keep the Garmin honest. If I see a large discrepancy in arrival times between the two than I review both routes. The Garmin has tried to loop me around an area when I know the area is okay to travel through.
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