I owned a Seafarer for 10 years..Slept on it all the time. Heck, slept two many times..Slept with my head aft, feet facing forward. The V-berth makes for a better choice for 2 than the Gulfstream.
I currently own a 232 Gulf and sleep in it for 2 weeks at a time on vacation. NO prob...can't wait for the next trip.
The upper bunk in the 232 works, but is not ideal. This configuration technically sleeps 2, but the Seafarer, as I said is the better choice for the second person.
Also must mention I am 5' 11" and stretched out on the Seafarer and my Gulfstream.
I suppose everyone's tolerance level and preferences are different, just like everything in life. If I had a Marlin or Sailfish, I'd probably just sell out and move aboard. I can't imagine having that much room below..That would be like a house to me.
Looks like your best move is to get in those cabins yourself and make the call. I would NOT have bought my 232 if I couldn't slept on it..That was my main focus.