It's the lack of storage that blows my mind as much as anything.
I know someone who lives in a 2-bed flat, which has an airing cupboard and two huge built in cupboards. I'd rather that any day.
I've lived in a tiny house with DC and it makes everything so much harder. For a couple with a friend coming to stay now and again, that house would work, provided they didn't have any hobbies that involved any kit like climbing equipment, or motorbike leathers.