Kenzo is like that person you feel a bit sorry for because they just seem to be forgotten / lost in the crowd. The taste is average but it's a convenient choice if Sansotei across the street has a huge line, or you have a vegetarian friend. I would pick Kenzo any day over Ajisen, but ultimately head down the street to Santouka for a better meal.
Pros:
-lots of noodles (probably double the standard at Kinton / Sansotei)
-quick service
-good vegetarian options. Most soup bases at the authentic places are pork-based
Cons:
-lack of depth of flavours / heartiness in the soup base
-price is the same as authentic places