I know you'll likely never part with your Dad's plane, but if you ever did...what would you get?
I have pondered that very question. Even my dad once thought of trading up to a '65 182, but then decided to do the 180 hp engine conversion in the 172 instead.
Sometimes I get frustrated with my airplane's skimpy 40 gallon fuel capacity. The -235's 84 gallons might be nice, even at 13+ gph; or even the 65 gallons of a standard 182 fuel system. Some extra power to deal with higher terrain out here would be welcome, too. Both the 182 (pre 1977) and -235 can use mogas, but the nearest airport with mogas is 200 miles away from me, so that's not a factor.
I like having two doors, but have gotten along with one when I owned low wing airplanes, and when I flew for a Piper dealer, years ago. (It wasn't an option for my dad, who suffered greatly with claustrophobia. He HAD to have a door next to him, and he was fine in the 172.) But then I like the visibility from a low wing. A 182 does better in short fields and unimproved strips, and has only 1/3 as many oleo struts to maintain.
So the pros and cons just about balance out. All else being equal, the tipping point for me, living and flying here in Arizona, would probably be the welcome shade from the 182's high wing, and the big openable windows.
But then all else is not equal. It's not like we're talking about new airplanes, where one 182 or one -235 is just as good as any other. These airplanes are old enough that there are no two alike, in total hours, maintenance history, equipment, mods, and overall TLC. Each individual airplane has to be judged on its own merits, and you find the best deal you can, whether it's a 182 or a -235.