I brought my brother here for a haircut a couple weeks ago, and it's exactly what he needed.
Just walk in, take a seat, and one of the barbers will call "next!". It's an old school barbershop, and everyone is pretty talented. $20 for men's haircut, good haircut, can't beat that in DT Toronto.
There were 3 people ahead and the wait was about 20 minutes. And remember to bring cash!