Garmin Zumo 590LM vs Zumo 660, should you upgrade?

In this video I compare the new 590LM with the 660 and advise whether you should consider upgrading. Donate to the channel using Paypal at https://bit.ly/2L8zAge The Curvy Roads "Road Test" referenced in this video can be seen here https://youtu.be/evZueHsSUDE.