Having had Sansotei several times, I decided to try out Santouka and compare the two.
My first experience was before I even sat down. If you come with a group, Santouka won't sit you unless your entire party is present. This can be quite bothersome because if other party members happen to be late for whatever reasons you'll be left standing just inside the doorway until everyone gets here.
The noodles were good but I prefer Sansotei's because I feel theirs had more volume and depth.
However, Santouka had a larger variety of flavours and their soup was lighter. Only downside was the greater dose of MSG used and as someone who doesn't like MSG at all, it's a sad realization.
Final point is the size and cost. Santouka is a bit more expensive for a slightly smaller size. In an overall comparison of depth of flavour and portioning, I don't think the ramen here comes in a better value than at Sansotei. Regardless, the food here is still delicious and would definitely make a great second option for ramen in Toronto.