I haven't read the stickied thread, so I can't compare to that, but my quarantine practice served me well for 20 years.
I used a bare-bottom 20 gallon tank with pieces of PVC in different sizes (2, 3, and 4") for hiding places. An Aqua-Clear 300 for biological filtration, Bak-Pak (later years) for skimming, and a simple hood/light...oh yeah, and a heater.
EVERY new fish went into a 4 to 6 week minimum quarantine. Any fish that showed signs of parasites went into a separate tank for coppering if it would be tolerated by the fish, and a simple cycled sponge filter and heater placed in the tank. They were kept in the coppered hospital tank for 4 weeks, then reintroduced to the quarantine tank for observation for 2 more weeks. If there were no signs of problems, they went into the display tank.
Fish that don't tolerate copper were treated with hyposalinity for 4 weeks.(was I ever glad when this technique was "invented" and refractometers were readily available) Hypo'd fish were kept at that salinity level for 4 weeks minimum, then brought back to tank parameters slowly, over about 1 week, then after 2 weeks of observation, they were put in the display tank.
I lost an entire tank full of fish in the old days because I didn't quarantine. That was a learning experience for me, and I changed my ways.
Since then, I've only NOT quarantined 2 fish. One was a 4-5" sohal tang that came from another hobbyist whose procedures I trusted, the other was a 4" CBB that also came from another hobbyist's tank who was meticulous about quarantining his livestock.
I never did quarantine corals or other inverts, and I know I should have...most got a quick rinse in fresh-mixed saltwater before being put in the display tank.