4S, Sun, Tokyo differences
Squiggy's right. The employees at 4S operate as if they're professional, trained, independent contractors paid on salary. The much nicer building and rooms probably plays a role in that, too. The only downside is there isn't much turnover.
Tokyo, OTOH, seems more like the employees are paid hourly and aren't as trained or experienced. The working conditions aren't as nice or spacious as 4S, and the service and staff are much more inconsistant and transient. There's more variety at Tokyo than 4S but that often means poorer performance, too.
It's sort of like the difference between a fast-food restaurant and a good, regular sit-down place with waitresses. You rarely see the same counter people in a fast-food place over a period of time, whereas the employees waiting tables at a restaurant usually stick around a bit longer.
Sun is somewhere in-between. The service is often (but not always) as good as 4S, plus there's some variety.