My 9 year old wanted fun tank decorations so we opted for it in the QT tank. I added a bubble wall to help with oxygenation since there isn’t much surface agitation.
I bought these from a LFS that was getting all new tanks. I have true union ball valves on them so I can shut one tank down or isolate a tank if I want to. Both tanks are plumbing into one sump. I don't recommend this kind of setup for everyone, but I was stocking a 180 gallon and needed a bigger qt system. And I am experienced with quarantining multiple fish at one time. I do still have just a 10 gallon qt tank in case I have just a small fish I need to qt. It has a light, hang on back filter, heater, powerhead and a sponge filter.