Originally Posted by bennos

It's impossible to say for any given flight, and you'll get anecdotes from some posters here about how easily they cleared and from others about how their certs went into the trash unused.

The way I would look at it is this: If you're OK with sitting in Y if they don't clear, go for the certs. If at least one cert clears, you've gotten better value than any other choice benefit. If you're not OK with sitting in Y if they don't clear, then find another way into a premium cabin (pay for J outright, buy W on another carrier, redeem miles, etc) and don't bother with the certs.