It is, because it has to deliver heat from the bottom at high temperature and for a pretty short time (around two minutes); it's not that unusual in Naples to have a wood oven in our vacation homes, but in the city many live in condos so it's impossible.

Leopard spots, also called "maculatura" or "mako" in some pizza-lovers forums, is considered by some a mark of perfect maturation of the "panetto" (the little bread, i.e. the dough used for a single pizza); to be honest it's quite a mystery to me how to obtain a good one, and as it often happens in this matters reality tends to conflate with legend: I've also heard sometimes that it is a sign of temperature mismanagement of the panetto, and I am not experienced enough to have a say on this :)