To me, the biggest benefit of overbooking is lower fares. If airlines didn't play the statistical overbooking game, most flight would depart around 10 percent empty - which would have to be recovered by higher fares for those who fly.

That said, and having taken IDB compensation more than once, I'll go for the voucher rather than the ticket any time if given that choice. I stand a darn good chance of actually being able to use a voucher.