I'm not familiar with this Schlotzky's and I've never been to Quizno's (lol) so I can't comment on either. I do love me some Subway, though.
MAF: Whenever people ask me for "light mayo" I always verify whether they'd like a small amount of regular mayo or if they want the low-fat mayo. (FYI our light mayo is not fat free, which is kind of unfortunate, because southwest is loaded in fat and I like to mix them.)
Best subway sandwiches:
Italian BMT on Italian bread with American Cheese, pickles, light mayo, and southwest sauce.
Subway melt on Italian bread with shredded cheddar cheese, light mayo, and southwest sauce.
Chicken teriyaki on a wrap with lots of shredded cheddar cheese and sweet onion sauce.
Turkey with American cheese on honey oat with a small amount of lettuce, cucumbers, pickles, light mayo, and a bit of honey mustard.
Steak on Italian bread with American and shredded cheddar cheese, lightly toasted, with jalapeņos, lots of southwest sauce, and a small bit of Frank's red hot.
MMMMMM.