I've had two narrowboats in the past, one of which I lived on for a while, yes it is a lifestyle choice and a very pleasant one, However, it can get cold and damp in winter, if you don't have a mooring you can only stay in one place for two weeks, I've had frozen water tanks, frozen diesel... if I didn't have to work I would again get afloat.
Btw the diesel is the cheap bit... you use red gas!
That particular boat you posted is ideal, purely for the mooring!
Oh and heels and wet decks...... I can see Freddy taking a swim