I've been shooting a lot with a 180 (chrome), and I like how the results, but for indoor work it does require a lot of room. On the other hand, i've been doing head-sized objects in a standard dining room (60's split-ranch), without feeling that I was had my back to the wall.

The only other consideration would be what lens you already have. If you're doing the occasional portrait, and already have the 80, then the 180 gets you a little over x2 in focal length, which may be more important for when you want a long lens in other settings.