Pros are good at the game, and like diamonds, enchanted armor/swords/tools, pretty houses, and bragging about their richness. They also like to kill noobs for fun, always laugh at them and insult them, because of their poorness and little knowledge about the game. Pros have stacks of diamonds, ore blocks, and are skilled craftsmen, fighters and miners.
They like to stay alone or in small groups, and are independent. They think they can do everything alone. They have much knowledge about Minecraft, almost always capable of surviving and doing what they want. They are really good at PvP, and often group in PvP Arenas.
In general, they are the opposite of hackers, always playing legit. However, they are easily trolled by, for example, some Minecraft updates, the ones replace their Diamond gear with useless items, such as Wooden or Dirt armor, or making another pro's Diamond armor and sword to be invisible, so they think they are noobs and rush into them, only to be slain easily.