Please note in my post that I qualified my preference for separate radar and plotters/depth/AIS. displays with the ideal that they both output those displays to a PC or laptop screen...where the helpful overlap function can be combined or overlaid. I do not object to the practice (although it can make a screen quite cluttered), but to the idea of having a single screen to access multiple and discrete devices, which I think is folly. Same with the display at the helm...make it a "remote" if you wish, to the nav screen in a protected place where you can also use paper charts. Otherwise you are stuck at the helm in sometimes poor conditions trying to deal with information on the screen plus information from the environment, like the sound of distant engines, breakers or hard to see nav lights atop rocks.
And then the helm display shorts out, and you are rummaging for a chart tube and a handheld GPS?
No thanks. Better to keep this stuff out of the way. A boat in no sense moves so fast that you need constant "live feeds" anyway, and if it's bad enough to actively helm, it's bad enough to have the entire crew up and working on the nav while you handle the wheel.
Again, to reiterate: software will accomplish on a laptop (or a flatscreen in the saloon, if you wish) exactly the same integration of radar, AIS and plotting as on a "marinized screen" that, if it goes, will leave you blind in the electronic sense. That's why I'll have a bunch of little displays, one 7" radar at the helm, and a PC screen velcro'd in place to show me details as needed. If the PC goes down, I still have all the elements in place, without the glitz.