By the way you’ll need lightmaps in stingray too ! It’s called BEAST and it’s basically the same thing as lightmass in unreal. Apparently the link between maya/stringray isn’t a big deal. (read it on cgarchitect’s forums)
And as far as I know, not many people are doing realtime arch-viz so it might be a good time to jump in.
realtime walkthrough / movies / virtual reality walkthrough / 360 panorama’s…there’s a lot you can do with unreal.