2009 Audi A4 or 2008 Infiniti G35?

I'm considering the Audi A4 (the new model that just came out) in either the 4-cylinder, or 6-cylinder version. I've always bought Infiniti's and I've grown fond of the them. I'm mostly leaning towards buying the G35. However, I wanted to try something a little different. I've heard that Audi's can be really unreliable, and are a pain to repair (high cost). Is this true? Also, what would really set the Audi above the Infiniti?