Can't see it mentioned above, but there are quite a few different types of 'fast track'
Airline staff etc
Elderly\Kids etc (used to be common in South America)
Diplomatic
Premium pax (e.g. BKK)
Ultra Premium pax (e.g. CK, Premier)
Paid dedicated assistance service (e.g. DOH)
Lounge service adjunct (e.g. PLS)
High End Assistance (e.g. Windsor Suite)
What you get differs.
I can't claim to have done all these myself, but I am beginning to see the matrix of possibilities look a lot bigger than can sensibly be handled in a single wiki.

Wasn't there a previous thread where different airports were rated as to whether OWE/S got you fast track through departure security? That at least seemed tractable.