A hybrid system is ideal. Lowers server costs all around. I think for lightweight files, p2p alone would suffice. Heavier files would require some sort of serve

A hybrid system is ideal. Lowers server costs all around. I think for lightweight files, p2p alone would suffice. Heavier files would require some sort of server based system. But A hybrid system would be tricky to implement. (The web rtc approach in instant.io maxes out at ram size.)