We've taken lots of bumps when it's fit our travel plans. Every time, our luggage has flown on the flight we'd planned on taking; the airlines don't postpone take-off to look for your luggage. We've found our luggage locked in the baggage office of our destination airport. Interestingly, one time when we took a bump, we arrived at the destination before our luggage, as our bags went on the original, connecting flight and we were bumped to a direct flight!
In the instances when taking a bump has required us to stay overnight somewhere, there's always been a complimentary hotel room and the airline usually provides an "essentials" kit, usually containing a toothbrush, toothpaste, comb, deodorant, foot covers (socks with grippy things, like you get in the hospital), and a tee-shirt. That's my experience.