The original National is retired, yes. He still uses the replica on Telegraph Road, right? A good tech can set up any guitar, including Nationals, to play like an electric if so desired. I don't think comfort has anything to with it. Unless the neck size (the Schecters, early Pensas) is very wrong.
As for jbaent's incredibly sarcastic and snarky comments (forgot your coffee today?), Mark's tastes have changed over the years. Suddenly he was gifted a Dobro-style guitar by Jerry Douglas, and then he very likely felt that guitar sounded nicer (more mellow) for Romeo. Hey, the man suddenly started using Kempers, for goodness sake.
Why don't we ask Guy?