Mismatch

Weapon system vs weapon.

Tam posted this video:




It's got some F-106A in it and shows a firing of an AIM-4 of some sort The close-up is an AIM-4F, a semi-active radar homing version.  The longer shot is more than likely an AIM-4G (heat seeker) because the D had been eliminated from stocks by 1973 and the way it goes all snakey from the rail.

The AIM-4 is much maligned.

The heat seeking AIM-4D Falcon was a miserable failure when employed against fighters in Vietnam.

This will be something of a lecture.

The USAF was not particularly pleased with the performance of the AIM-9B Sidewinder over Vietnam and the AIM-4 in the century series fighters nearly always outperformed it in range testing.

The AIM-4D is the seeker head off of the AIM-4G bolted to the body and wings from an AIM-4C and coupled with a special launch rail just for the F-4D Phantom.

As they compare to each other.
     They are both heat seeking missiles.
     They both require active cooling of the seeker head.  This coolant in both cases is stored outside the missile.
     Both were developed to attack large, unmaneuverable bombers.
     The AIM-4D has a larger warhead, 18kg vs 4.5kg.
     The AIM-9B has a proximity fuse and a fragmentation jacket around the warhead.  A near miss can damage the target, the AIM-4D has to make a direct hit.
     They both have a similar field of view and seeker tracking speeds.  The AIM-4D has a more sensitive seeker and can be fired from a wider cone behind the target.
     The AIM-4D takes much longer to cool down to operating temperature (5-7 seconds vs less than a second) and takes much longer for the seeker to acquire the target (2.5 seconds vs half a second).
     The AIM-4D needs some flight time to "gather its wits" and needs more nose-tail separation to fire, thus it has a longer minimum range (just under a mile vs about a 1/4 mile).
     The AIM-4D has a longer range (about six miles vs about two).  The rules of engagement that required visual identification of the target meant that the longer range and more relaxed envelope of the AIM-4D were never taken advantage of.
     Both missiles, even when employed correctly, are still fairly easy to defeat by simply making a hard turn and moving outside the seeker's field of view.

Philosophically they are very different.

The Sidewinder is nearly a stand alone system.  There's a small tank of coolant in the missile rail and some wiring.  The wiring is very basic, just an arming circuit, firing circuit and a lead to give an audio tone to the pilot.  The Navy developed the missile with the idea of being able to retrofit it nearly any guns-only fighter in its inventory.

The AIM-4 was developed to be part of an integrated system in the F-89H, F-101B, F-102A and F-106A.  This included ground stations, the plane's radar, a computer and the missiles themselves.  The AIM-4D was paired with the radar guided AIM-4A missiles in the Delta Daggers and Delta Darts.  The fire control system communicated with the missiles and the radar scope gave the pilot a lot of cueing to get him into proper firing position.  The supply of coolant was fairly large and contained in a tank in the aircraft.

When the AIM-4D was adapted to the F-4D the fire control system from the F-106 was not brought with it.  The rail lacked the volume to mount a large supply of coolant, there was just barely enough to bring it to ready status.  The interface between the missile and the plane could be described as spartan.  A ready light being the only indicator that the missile could be fired and the pilot (and WSO) needed to do his own calculations about whether he was in a good firing position.  It was very easy to end up too close and have the missile be unable to see the target by the time it went active.  It was very easy to not notice that the ready light had gone out because the coolant supply had been exhausted and the seeker was no longer working.

Foreign nations that adopted the Falcon were paying attention and incorporated derivatives of the Hughes fire control systems.

It certainly didn't help the Falcon's reputation that the Navy had deployed their improved AIM-9D Sidewinder by the time the F-4D was ready with the AIM-4D.  In fact, nearly all sidewinder kills by Navy aircraft in vietnam were with the D version.

One reason that it is much maligned is because it was kludged onto the F-4D when the AIM-9B turned out to be an epic disappointment in the F-4C Phantom.  Ironically the Air Force did far better with their AIM-9B's than the Navy.