You can sort of avoid the obsolescence with an iPad/tablet, but you only get really good maps/gps with that, and the over heating and screen visibility in sun light, can cause issues. I have a Simrad, and I like it so far. The boat had an old heading sensor, and I was able to integrate it into the network with a 100$ NMEA 0183 to NMEA 2k converter. The Simrad comes with dock to dock auto routing if you buy Navionics maps for it, but compared to my iPad, it’s painfully slow to calculate the map. The iPad calculates the route in seconds, the Simrad (NSS EVO3 9”) takes a good 45 seconds, so I don’t use that feature on the simrad. Garmin now owns Navionics, and I can’t speak highly enough about Navionics maps, and the apps they have produced to display those maps on iPads/android tablets. The apps update frequently, the maps update seemingly daily, and the ease of getting those updates is amazing. Plus, anywhere I go, I can plan my trip in my hand.
I wish the manufacturers would sell a system like an iPad, easy to use, constantly updated, integrated cellular/WiFi service, but has the sunlight readable display. Should be able to quickly disconnect from the boat, and take it home, so you can plan trips, review tracks, and depth readings. By taking it home, you also prevent theft and increase the longevity of the hardware.