One year while shopping for college supplies, I picked up an aluminum T-ball bat. I lovingly called it "The Attitude Adjuster". When the guys I lived with and I would razz each other, often times we would pick it up and threaten each other jokingly. Never had to use it to defend anything though.

It seems to me that when one is considering such a tool for defense in an enclosed space, the shorter T-ball bat might be a good option. True, the reach is less, but since using a bat as a defense tool is a short distance affair anyway, you will be less likely to clobber that heirloom grandfather clock or the curio cabinet with a T-ball bat.

I don't know as in a situation like this if the physics of wood vs. aluminum or plastic for distributing force and such will be as important. Remember that most criminals do not want to fight someone...they want to dominate someone. A good whallop from a bat will immediately start the BG thinking that he picked the wrong house. Broken bones serve as a good wake up call of course, but the object is to eliminate the threat, whether he ends up broken or merely bruised.

Cold Steel's Brooklyn Smasher and Brooklyn Crusher look like fun options for bat defense IMO.