That part I could actually understand- then don't exactly walk around with the faceplates popped very often (except for one scene in IM2's finale and the party scene, where it makes sense), especially when "on the job". Spoiler Actually, that part I thought did put Tony in danger- the Mandarin and his Enhanciles were going through suits like paper towards the end. It really seemed like Tony was going to run out of suits eventually. However, you've also convinced me that there is a very good chance Tony has Extremis, or, at least, some variation on the tech. I have a feeling that's going to be the big Avengers 2 reveal when Tony suddenly deploys an Extremis suit. Naturally, it'll be spoiled in the very first trailer . They did do some concept art for an Extremis nano swirl thing so they've at least explored the idea.