A couple of weeks ago I flew on this Pacific Coastal Beech 1900:

http://www.flickr.com/photos/geoff_a...ia/3367333856/

Definitely smaller than an RJ of course.

I sat in the last row of the aircraft, which was in effect a three-across bench seat. Behind me was a thin flimsy bulkhead, held on with a few brackets. I could plainly hear the luggage being taken in and out of the plane at our stops along the way to my destination - So while there was no access to the luggage from the cabin (without some tools) it was plainly obvious where it was.

...and I must admit I didn't get the sense there was any complex luggage balancing going on, unless 'huck the bags into the hold' is some new complex system I'm not otherwise aware of