Wow, thank you for your detailed answer, but one question about:
"1 in 3 packs will include a traditional foil card that replaces one of the ten commons in the pack. This traditional foil card can be a main set card of any rarity; a new-to-Modern uncommon, rare, or mythic rare; a showcase treatment card of any rarity; or a borderless rare or mythic rare."
Will the set booster include in every pack the traditional foil card? So not the proportion of 1 every 3 packs? I am looking more for the collecting part, but also for the "open booster experience". The collector-display are way to expensive... It means it is too much money for that less number of booster for me.
Is the set booster the best "middle way" to open booster and also get some "special" cards like showcase, the fetchlands etc.?