I really dislike wandering around wondering where to eat at the end of a long day of touristing, especially when I have to compete with other tourists like myself.
How far ahead do I need to make dinner reservations at a place like La Bitta or Osteria Bancogiro? Do I phone up (or ask my hotel to phone) three weeks ahead? Can I pop in at lunchtime the day before to ask in person for a reservation for the next night?
A place I wanted to go in Rome seemed to require a reservation 60 days in advance. I never got there.