Ease of navigation is excellent on my units. I have the echo map 70's 7" touchscreens with the gcv 10 box for side and down vu. Only had them since March but I like them better than my 998c I used to have.
Good luck finding the units I have though, they went on sale in February for half off and disappeared quickly. Should be several reviews of the 73 or 93sv coming out in the next few months