This is interesting! I am another one that learned and used street (dress) shoes for many (MANY) years, I used to hold my feet somewhat sideways since they were wider. When I got my Hauptwerk setup, I finally ordered a pair of organmasters. I just never really felt comfortable with them, I can't say why. Perhaps it's as simple as the hassle of tying and untying!
I really like the idea of slip-ons, since I am lazy!