Radio vs Infrared

I know this has been mentioned many time, but I was wondering if anyone has used both system and which system they prefer. I currently have a 430EXII but I am looking to buy a 580EXII and another 430EXII along with some light modifiers, or 2 PWTT5 radio triggers with a 430EXII and some light modifiers. I like the idea of having the 580EXII so i can still have a bounce flash on the camera but I also want to shoot outdoors and I heard that this is where infrared fails miserably. Thanks for the help!