I have been a regular MS patron since my school days in Toronto. I have had literally thousands of subs from their locations, and I can say that MS is a sort of institution. Okay, so maybe I am a little less than objective.
The North Shore MS is pretty typical of the 'new look' for the franchise. Gone is the all red and white with the tacky wallpaper and white smocks. Now the place looks like they sell cell phones or hair products, with pastel colors, etc. Except for the piles of meat and veggies and the display breads at the counter, which is a reminder of what you can actually buy there.
The menu has too many choices these days, and I still tend to get the assorted or the super-assorted, although I have tried most of the sandwiches they offer. In the past they used to get their breads from a central bakery, but now most locations make the bread on site like at Subway. For some reason, the MS bread tastes better in Ontario, but I am not sure why.
Service is usually satisfactory, with the occasional bit of banter from a bored counter clerk. I have always found the locations to be clean, and the food seems fresh enough. As for value, there has been some price creep over the years, but is it still solid value for the money.
I 've had lots of conversations with friends about what constitutes Canadian cuisine. Mac & cheese? Beer and Cheerios? I think Mister Sub is somewhere near what I think of as Canadian food.