Homing's greatest difference is among different types missiles.
Most missiles seek flying targets better than grounded targets. This is especially important to Anti-Air missiles.
Missiles that curve weird without lock, like V-2 way missiles, only "home" into the spot where they once were, they're really really inaccurate.
Pulse Missiles, such as Tentroin HD and Helingale AM, seeks better the higher up you are, I have no clue into the specifics.
Anti-Ground missiles, such as Geograsis AM4 and Poseidon AM, homing better on grounded targets rather than flying ones.
There are a few notes about the distences regarinding missile's homing.
The firepoint, where the missile is shot.
The activation, when the missile starts to seek.
The cut, when the missile stops seeking.
The range, when the lock goes poof.
Most missiles have activation right after firepoint, and then cut is near the range.
IE, fa----------cr
Snail BD has a long time before activation, cut is fast, but range is far. Makes it inaccurate.
IE, f----a-c-----r
Gathima AM2 has the longest time between firepoint and activation. But it does have amazing homing. I have no clue when this thing cuts.
IE, f---------a--r
Just a few notes.