I've only got an enchanted diamond chest plate (P1) with an enchanted diamond sword (S1) and full enchanted iron (P1) for the rest, but I've killed players that have enchanted full diamond when I've had chain and gold stuff with a stone sword (With 6 hp left, so yeah) Honestly as long as you are good at pvp and use things like TNT and bows, like Electric said, then you can easily beat most people with good skills, but these are just my words, and im pretty bad at sg, so yeah.