I use Lakemaster in the birds and Navionics on an iPad. Both are good, and both have different features that are better or worse than each other. I like the GUInon the iPad. Very easy. The birds are a PITA to zoom and reload. Also, at times, the maps on the birds are too small if I am splitting the screen up with DI/SI/map. And the other two screens are mounted on the bow. So they are only used when trolling.
My assessment? Any map is good enough. Any map is way better than none. Any map is limited by the hardware using it.
RIP little Nitro