Placing an ambience mic is never a bad idea. If you can place more than one in different places of the room, they will just give you more choices.
A good ambience mic, placed high on a corner of the room, or just close to the ceiling (granted you have a high ceiling) can give you that “roomy” sound, with some reverb and slap to it. The higher you go, the more cymbals you should get. But also, try ambience mics closer to the ground to get more low end.
Use your room. Try to exploit every single corner you have at your disposal.
Depending on where you place that room mic, it can add a lot of character to your drum sound. Just as an example, here’s a video by Kenny Aronoff with a 5-mic set up of 2 OH’s in spaced-pair, bass drum, snare and ambience mic.