For navigation the Garmin's white arrow is clearly way superior over whatever the wahoos and magellan turn prompts/navigation aids.

But the 520 Plus processor is definitely overtaxed when navigation is coming in thick and fast. The graphics would freeze and i can't see my blue location icon....so i don't know exactly where I am in an upcoming turn.

My car's Garmin would re-route in an instant after i've gone past my turning .....the 520 Plus would refuse to re-route. And when it does it would take forever to re-calculate....by that time you might already have found your way (hopefully) or given up. And it would still might probably say Off-course that means it's too much for my tiny processor to process.