The hotel is very much in the center of Bangkok
MRT across the street can take you to Terminal 21 shopping center without any transfer. It's always a very popular, very crowded place for locals and tourists alike. The very cheap food court on level 5(?) must have something to do with its popularity. Entrees and dessert like sticky mango with rice can be had for around 30 bahts - less than one US dollar!
The hotel also has half-hourly tuk-tuk service that takes guests to (also popular) Silom Center mall/Sala Daeng skytrain stop.