its not that bigger is easier ...bigger is more forgiving.for things alot of new reeferes find frustrating.
lets say you get a head of aiptasia on a frag, in a large tank it would take more time to become a problem where it spread over every rock , whats a problem in a large tank is a plague in a nano...... this i know
water issues are going to be roughly the same ,if your cutting cost out of the equation a water change is a water change and media is media, fact is a nano is cheaper to run financially though.
i know in a large tank fish problems are way more forgiving then in nanos, lets face it very few stick to actual "nano fish"
people tend to feed small tanks the same as large tanks which leads to problems and if your like me people fill their tanks with corals as if they are larger tanks.
i think both large tanks and small tanks have problems unique to them so neither is my vote.