I'm not sure what kind of "luck" you'd expect. I think of the EF alerts for waitlisted segments as a backstop. In a perfect world, the airlines would clear upgrades/awards directly from the waitlist and never release the inventory publicly. However, this doesn't seem to be the case most of the time. There usually is some delay between inventory release and waitlist clearing sweeps. Obviously, the shorter the delay, the "better" the system works, and the less useful ExpertFlyer is fort his sort of thing. But often the delays are longer. If the stars align and EF checks the alert after the inventory dump but before the waitlist sweep, you'll get a notification and the chance to potentially jump the queue (for better or worse). But often the processing will happen before EF checks. That's fine. You still got your upgrade. The odds that someone else got in before you either because of their own EF alert, or by chance, are probably very very small.

And by the way, I actually find EF alerts more valuable for non-upgrade situations, where you can't waitlist directly with the airline. I use it a lot for revenue fares, perhaps to notify me when "I" inventory opens so I can grab that $2k business class fare to Europe, or when "O" inventory opens so I can get that $89 ticket to Miami. Or even on the reverse -- I can have it notify me when "O" inventory drops below, say, 5, signaling that I should probably buy my ticket now. You can also use it for flight award inventory (Z/U/T) either to alert you when you can go and book your honeymoon to Hawaii, or when you can switch from the early morning JFK-LHR flight to one of the redeyes.

On United (previously Continental) it was very handy for doing confirmed flight changes, which have to be booked in the original inventory class. Even on a rather full flight, the cheap classes would often open up a few hours prior to departure, and I was quite frequently able to make the change promptly thanks to an EF alert. You could probably use this on AA too, looking for the appropriate inventory (I think any CFC comes out of E or G or something).