Originally Posted by Thunderroad

I can't speak about Emirates, but I use ExpertFlyer frequently for American and occasionally for other airlines. Basically, I subscribe to it and like it a lot, and it generally is correct if it shows upgrades or award seats available. But occasionally when I call AA the phone agent will find upgrade/award availability that hasn't shown up on EF.

A few other pieces of EF advice:

1. Occasionally if you look for availability from point A to point B and/or from B to C, you'll find it whereas looking for A to C (via B) doesn't show up at all. For instance, with AA I occasionally find that if I simply search for economy to business upgrades from SFO to LHR, it won't show availability even though LAX to LHR is available and should show up as part of the SFO-LHR search.
2. Conversely, even though EF correctly shows availability you might have to ask the phone agent to check A to B and B to C if she can't find A to B to C as one search.
3. Some phone agents are better than others, so if you encounter one who sounds unhelpful or ignorant in trying to find seats that EF shows as available, just politely HUACA (Hang Up and Call Again).