Kasha‘s place is super convenient - it’s a very small room for a small price in a lively area! Convenience stores all around, few minutes walking distance to Shinjuku line and Marunouchi line, Golden Gain is very close and you easily get to the other city parts.
Place is very accurately described, you will prob hear the traffic a bit, but you have everything you need for a good stay in Shinjuku and surroundings!