I worry about the cure all's because I'm not sure they're effective enough for each purpose. I do like sea chem products, and I trust them overall.
My QT is prazipro, 2 treatments 3-4 days apart (flukes & worms), then 3 weeks CP (Ick Sheild powder). Quicker on the ick sheild if I were to see ich or velvet. Metro in food for internal parasites if I suspect any, Futan 2/kanaplex are also pretty good for the bacterial issues. I use Focus to bind medicines to food.
Thing about copper.... it has some downsides, but it flat out works. Hard on some fish though. . Hypo, Paraguard are not 100% in my experience. Much, mich better than nothing though.
Thing I like about CP and even praziquantel is that they're one and done (providing you don't have bright lights or substrate).