weak processor plus super small power source - battery. When a turn prompt come up you get that wonderful big white arrow but often you can't see your location icon....so you don't know where you are if not for the Distance to Next countdown. Sometime you'll see the blue location icon floating in but most of the time unless you're walking the blue icon never turns up....the processor seems to be overwhelmed.

My theory is that the 520 Plus - as we know is the 520 of years ago - may not have the necessary processing GPS power to perform optimally. So there's been no hardware upgrade/improvement to the 520 Plus - it's heart is the same old 520. The software is doing whatever it can in light of the weaker processing capability of the 520 PLus.

The 520 Plus probably has one of the better color screens - it's not touch sensitive so there one less layer of screen (touch resistor or whatever they call it). I find it quite clear for a color screen - i've got the Cyclo505 and it can be quite hard to see clearly most of the time. it's sharper than the Cyclo505 and the GPSMAP 64s and the Oregon range.

The up front mount in the box is a touch too long for something as small as the 520 size. It's probably from the 1030 stock. It puts the unit quite a bit further away from my eyes. I am using a shorter mount instead.