I don't eat ramen very often, so I can't compare this place to others. Misoya is small and underground, but nonetheless when I came at 14h30 on a Saturday, all but one tables were filled.
I ordered the spicy Kyoto style ramen, and it was quite good. The broth was smooth with a bit of sweetness. There was a substantial dollop of spicy miso on top of the noodles, so you don't have to make the soup super spicy if you don't want to - just don't mix in all the miso.
I am taking a star off because it's hard to impossible to eat vegetarian here, and I don't think they're very flexible with their menu choices. I asked to substitute Naruto for cha-shu in a dish, and they said no. Apparently, Naruto is reserved for only one of their dishes.