Do any of you hardcore option guys know if there's any advantage to selling-short "synthetically" via the options?
One disadvantage is the amount of time it may take to get filled in the options market. If you're arbing the stock in any way, you may have some slippage. This has been a problem with single stock futures (SSF) as well due to the lack of liquidity. Also, keep in mind, if you're doing something in the options market, you're counterparty could very well be hedging himself in the underlying as well so there's a natural execution race / problem.
Selling short 'synthetically' also limits your risk (if it's a naked short) and keeps your resources free as you won't need to deposit more margin and pay the huge interest rate brokers charge for short positions.