some could argue the "aged factor" of the water sourced from DT, as apossed to sterile fresh mix, but im sure not going to..lol
Id still keep a QT seperate in every way from the main.
Seperate set of nickers for every occasion i say.
never underestamate a bottle of cycle if self presivation drives you down the bacterial path, corals are a different story all together so when your talking fish you gota use your head. the variables & factors involved have to be taken on board. If your new fish has just been shipped from the red sea, your going to be looking for stress & fatige & your not going to feed your new fish as much at the start cause a) they wont really want to eat, and b) the duration of travel im most cases would shrink the gut cavity anyways, thus resulting in less build up of wastes anyways ..aka ammonia........sweet sweet ammonia. um, yeah, where was i...arr yes.........where as the fish you've had your eye on in the store the last 2 weeks is already eating cause you've seen it before, & you've asked to see it feed right before purchase, so henceforth in the back of your mind trickle water changes could more than likely be on the cards to keep levels consistant.
cycled, non cycled, or SHD coined term "Hybrid" approach, it does matter, what matters is at the end of the day you use your gray matter logicly & perform small water changes often. right..who has my beer!