Justin Yoshida
Google
Solid menu and execution, but overrun by tourists. I would actually rate this place three and a half stars, but I'm rounding up.
I've also come to the conclusion that Chiang Mai locals actually don't eat khao soi that often - it's just a famous local dish of which everybody claims to have a best/original/unique version. To be brutally honest, it's just a tamed down version of laksa and usually not worth it.
However, this restaurant serves many other things as well, which is why it gets a good rating. These things are not on any English language menu as far as I could tell, but they are on the wall menus in Thai and some are viewable in pots as you walk into the restaurant. These include shrimp patties, vegetable and noodle dishes, stewed meats, and other interesting things. If you are not visiting with a Thai, I suggest looking at what others are ordering or flipping through photos on the FB or Maps page for the restaurant and pointing.