Business vs Economy
Serviced apartments in Tokyo tend to be some of the nicest options you could possibly have for housing. Many foreign businessmen choose a serviced apartment over a long term hotel stay, for obvious reasons of comfort, and avoiding the logistics of moving into a new place, dealing with Japanese realtors, finding furniture, etc.
A serviced apartment in Tokyo will likely be located close to the business districts such as Chiyoda and Chuo wards, with easy access to amenities and transportation. For the most part, a "serviced apartment" is as close as you can get to a lifestyle that you may have become accustomed to, that is, in the price bracket that a serviced apartment is characterized by; in the 300,000 yen a month range.
Space Design is a firm that has worked with foreign guests for many years: