I recently stayed in Kanayama for work. It was perfect for someone who wants to be in the city but not too crazy. Also, the train station is very convenient. Definitely look forward to staying there again in the future.
I visited Shinjuku about 10 years ago and absolutely loved it. The city was vibrant, clean and safe. It felt like a true Tokyo, Japan experience. Of course, there were many “girl” establishments but certainly no salesmen.
Fast forward to today, I visited Shinjuku again and it was a nightmare. More than half of the visitors were westerners and acting like fools, foreigners were being very pushy trying to get you to buy things or get you into establishments. I was followed a couple times. It was dirty (trash all over the street). First experience in Japan being uncomfortable, which stunned me.
Overall, this place didn’t feel like Japan and it was a really disappointing experience. Social media has definitely made Japan a more popular destination but it has really impacted the true Tokyo experience in this instance.
Edit: This is specifically in regards to Kabukicho and Golden Gai