Short Selling: Worthwhile or Not?

Most people short sell to profit in a bearish market and hedge the downside risk of a long. But, along with its appeal, come its many risks. A short position can be closed out at any time because the stock's lenders are demanding its return. A short seller also has to pay lenders for unpredictable events such as spin-offs and share splits.

So, in the long run, how has your experience with short selling panned out? Is it worthwhile?