If it's armor vs armor, Tony wins. Lex's power suits tend to be pretty simple. He's never made anything on the level of, say, the Extremis or Bleeding Edge armors.
Business vs business, Lex. Lex may be arrogant and prone to screwing himself, but Tony is too and he's a worse business man than Lex. Tony's lost his company a couple times while LexCorp takes no losses. Plus, Tony has ethics and shyt, which will absolutely fukk you over in business.
