I have a 78 31' Prout. I am 5'11". The floor in the nachelle has been lowered and I have 5' 8" at the pass-thru. Beyond the forward bulkhead has been converted to a perment queen berth with storage
under, which was convertable in original design.
In the rest of the boat galley
and nav area in the main hulls is fine for me and starts getting small as one goes to the ends of the hulls. The areas I live in are more than enough for me. Since I am either at the table for 6 with opposeing settes or in my bunk the issue of no standing headroom in the main salon is not a problem, I walk around all the rest of the boat.
All boats are a trade-off and this is one I took.