Despite being in the heart of Bangkok's nightlife, dining, and shopping, there isn't too much going on at the S15, perhaps due to the fact that the hotel is low on features and caters primarily to business travelers. The lobby area is probably the most popular hangout spot, and is often busy with people waiting for meetings, appointments, and pickups. There's also a lobby lounge for drinks, and in the evenings, the terrace area just outside the front door becomes a popular spot for cocktails and people-watching. Due to its solid meeting facilities, stylish rooms, and location near the Skytrain, plenty of corporate types frequent this spot, many of whom are from Japan.

The S15 is located in the heart of busy Sukhumvit Road in central Bangkok. It's in one of the top areas in the city for dining, drinking, and shopping, and there are dozens of restaurants, bars, and shops within walking distance. The Skytrain and subway systems can be accessed in just a few minutes' walk from the hotel, and the airport is a half-hour drive away. While one might think this is the perfect location, there are some downsides. The area has dense traffic, especially during rush hour, and the red-light districts of Nana Plaza and Soi Cowboy are nearby, so the neighborhood can feel a bit seedy at night, although it certainly isn't dangerous. 

While all rooms at the S15 come with stylish modern love seats, writing desks, 32-inch flat-screen TVs, stocked minibars, full-length mirrors, and free Wi-Fi, the rooms feel cramped, like they have a few too many pieces of furniture crammed in. Some of the rooms, such as the Jacuzzi Suite, feature a trapezoid layout with the furnishings in a line, but they still feel crowded. All rooms come have spacious bathrooms with tubs, although the Jacuzzi Suites have larger whirlpools. The rooms are bright, with the option of closing wooden shutter doors if the sunlight is too harsh, but the windows cannot be opened, so the rooms lack fresh air. The views are nothing special, as the rooms all look out on surrounding construction and neighborhood sprawl.

The hotel does not have a swimming pool, but it does have a small indoor whirlpool and a few lounge chairs up on the eighth floor. The hotel also has a small fitness center consisting of a treadmill and some free weights, as well as a spa offering massages and treatments. The Mezzanine Cafe is the hotel's only restaurant and serves buffet breakfasts (included at room rates). There's also a small bar in the lobby, which extends out to the small terrace in front of the hotel in the evening. Popular among business travelers are the hotel's business center and three conference rooms on the eighth floor with audiovisual equipment. The on-site boardroom on the second floor has an LCD projector and can seat up to 10 people.