Iron Lad spoilers
Why is the armor so advanced? Because Iron Lad is really from 1,000 years in the future: he's better known as Kang the Conqueror. If you're unfamiliar with Kang, he's a time-traveler born in the distant future; he grew tired of his peaceful world and longed to visit the more war-like cultures of the past. He's changed identities several times over the years - at any given point, he could be Kang, Immortus or the pharaoh Rama Tut. And now we can add "Iron Lad" to that list of aliases.

See, as a youngster, Kang was severely beaten by a gang of bullies. He later went back in time to "save" himself from this, but the boy he was didn't like the man he would become, and so fled to the past to get the Avengers' help in preventing his future. With the team disassembled, he downloaded an emergency protocol from the android Vision's remains and sought out new teammates to become the next generation of Earth's Mightiest Heroes. He even succeeded, for a while, but it screwed up the time stream so royally that eventually he willingly retook his place in history.

Oh, and as an additional note, when Iron Lad removed his armor, Vision's operating system gained sentience and now uses the armor as his new body - oddly enough, a similar thing happened with Ultron, Vision's creator, when his programming was moved through Iron Man's armor and began to take over.