Durability - both about the same
Accuracy _ navi wins hands down
good for dummies - navi can be a bit more complicated setting up but once done its fine
long-term usage - both need to be used in a aqua-pac
The navi also has an sd card which allows you to save multiple days sailing.
Most people are leaning towards the navi and its also slightly cheaper. it has my vote

.
ta vando