Having been to the Shinjuku location, I'm familiar with Anshin Oyado. This is my first time staying in Shinbashi. I like this chain because of the extra things provided at no charge. The worker didn't speak a lot of English but tried very hard to explain the hotel area. The locker was too small for a carry on but they held onto the luggage at no charge. Plenty of free amenities like drinks, massage chair, relaxing lounge and paid amenities like hot food and other drinks. I stayed on the 6th floor. The capsules weren't overcrowded and people know to stay quiet in the room. The train tracks can be heard right behind you, but they also provide free earplugs. The public bath area is a little small but still very relaxing.
The hotel is literally one minute away from the Karasumori exit, so it's very convenient for anyone who wants to stay near the station. Lots of bars and mini restaurants nearby to entertain. An Irish pub is also 2 mins away for anyone who wants to speak with English workers.
If you enjoy the Sento/public bath and travel solo, this place is very convenient and provides plenty to make your stay as comfortable as a capsule hotel in Tokyo can.