Better for both parties, if they have a long-term outlook.
I'd say you want to be paying a market rent so that your landlord is happy with you. It's in their incentive to keep you there and happy, and they're likely to go out of their way to keep you happy. If you manage to get locked into a contract to pay under market rent, then they will be unhappy with you and motivated to go out of their way to hurt your business and make your life difficult.
Granted, this may not be that common of a viewpoint in the restaurant industry, though. Or in the NYC rental industry.
I'd say you want to be paying a market rent so that your landlord is happy with you. It's in their incentive to keep you there and happy, and they're likely to go out of their way to keep you happy. If you manage to get locked into a contract to pay under market rent, then they will be unhappy with you and motivated to go out of their way to hurt your business and make your life difficult.
Granted, this may not be that common of a viewpoint in the restaurant industry, though. Or in the NYC rental industry.