You know, you really are quite set in your ways, old gray beard. The relevance is not that the "Cobra" is necessarily an overtly usable tactic in a modern battlefield, it is however a physically and clearly observable indication of the performance envelope of the airframe. From knowing the airframe can perform that maneuver, you can extrapolate out many other characteristics.
Obviously, even logical dissection is beyond your stubborn wiring.
Greyeagle is more right than you are, and I am confident that my sources and personal experiences are far more relevant than yours. Extrapolate all you want, but until you read the flight test report and the FWIC tactics talk, or actually take an F-15 up against a flanker or fulcrum, you have no idea whatsoever what you are talking about. But you can't, and never will. I spent over a year where I flew 4-5 sorties per month replicating fulcrum and flanker threats using the best available data, and I've worked with both former GAF mig-29 pilots and F-15C drivers who spent weeks flying DACT against the fulcrums before we had the benefit of our new helmet mounted sights and aim-9x.
Again, Grayeagle is more right than you are. I will go further to say that although the flanker is a very capable aircraft, the airshow maneuvers are not very good at all for extrapolating anything except how good the plane is at waving the nose around at low airspeeds. A well flown F-18 with some flight control software tweaks would probably be able to pretty much the same maneuvers, slightly modified of course to account for the lower thrust to weight ratio.
In the end, the aircraft and weapons are matched well enough that if neither side knows the exact tactics used by the other side, the edge is probably still the US F-15 due to the sheer number of flight hours an F-15 pilot gets and because of the very good cockpit ergonomics and system integration. If the flanker pilot knows the US tactics however (as I did whenever I "cheated" while replicating russian fighter threats), it then comes down entirely to individual pilot skill even without resorting to the radical maneuvering capabilities of the flanker. If they're both cheating, then the better pilot wins even though the flanker can pretty much turn up it's own butt, because the F-15 is easier to fly and tactically employ. Plus the amraam is a freaking deathstick, and 2 amraams coming at you are nearly impossible to defeat so the flanker's maneuverability may not mean anything in most engagements.