Have stayed here many times. Have also stayed at the Sheraton Bradley several times. They are both pretty close to 6 Flags.
Though I haven't stayed here very recently, a hotel has always been acceptable. Clean, comfortable, service is okay, and there is a pretty decent sports pub in the hotel with popcorn (a personal favorite). As mentioned, it is in downtown Springfield which is pretty dead after hours. Probably during the day too.
It gets the job done.