I have a narrower beam on my boat and am dying to put a 4' open array on it. Some would think it looks odd, some would think it looks cool. Personally I wouldnt care. I would want to see birds.
The 4' is not really that much bigger than the 3.5' arrays.
That is true that open array gives better resolution but mostly at distance. Unfortunately open array radars have a larger main bang so they are not as good in close range like for harbors than a radome. For navigation purposes in close range on a small boat, a good radome is better. Solid state the best.
I have a 4kw 24" UHD Furuno radome. However I want a 4' open array, the new Furuno X-band, radar but that is so I can find birds when I fish in southern Maryland beyond the eyes of my stabilizing binoculars. If I could see birds 5-6 nautical miles out I would be in heaven. Now I just need 5-6 grand laying around without my wife going nuts.