There are probably only 2 reasons to go to Mars at this, the original location. First, you’ve never been here before, and want to be able to say you have. The second is you haven’t been for 25 years and want a quick hit of nostalgia. It pains me to say it because I have fond memories of this place, but there are dozens of other diners in Toronto equal to or better than this one.
NB. I’m adding this post, from notes, over 2 years after the visit. This was actually the second visit after a decade-long absence. My main memory of both visits is the off-putting smell of disinfectant. In fairness, I would like to try this Mars one more time after having the experience of dozens of other greasy spoon breakfasts since this visit.