Pita Gyros Diplo (Διπλό) is the upsized order: diplo means "double," and depending on the shop it buys you a double round of pita, a double portion of meat, or both. It is the same sandwich as a standard pita gyros scaled up for a bigger appetite, and the only variable that matters here is structural: more load, and whether the bread is built to carry it. That is the whole question this entry turns on.
Done properly, diplo is more than a heavier filling stuffed into the same round. The honest version uses two pita nested or a single sturdier double-thickness round, both well griddled, so the base can take a doubled weight of carved meat, tzatziki, tomato, onion, and patates without blowing out at the fold. Good practice keeps the proportions intact as it scales: more meat, but also enough bread and a little more tzatziki and tomato so the thing stays balanced rather than becoming a fistful of dry shavings. The roll has to be packed tight and the base sealed firmly, because a doubled cone carries far more juice and will leak faster if the wrap is loose. Sloppy execution is the giveaway here: a single thin pita overloaded until it splits and dumps its contents, a doubled portion of meat with no extra sauce or vegetable so it eats dry and one-note, or a cone so heavy and badly wrapped that it collapses before you are halfway through. Reheated, greyed meat is twice as obvious at this size.
The point of diplo is portion, not recipe: it exists for people who find a standard pita gyros too small, and it is judged on whether the shop scaled the structure honestly or just charged more for a fragile overstuffed round. Some counters price diplo as double meat in a single reinforced pita; others genuinely fold two rounds together; a few read it as the full apo ola set in a larger format. The standard pita gyros apo ola it scales up from deserves its own article rather than being crowded in here; what matters at this entry is the doubling itself and whether the bread underneath was built to survive it.