Originally Posted by Excelsior.
Is there any article that makes explicit the exact power upgrades from mark to mark? Would be really helpful.
Not that I know of, lets do it in this thread. If we come to a solid consensus I'll add it to the OP. Best I can tell it goes like this:
Prototype, built with limited resources in unfavorable conditions. Miniaturized arc-reactor allows for defensive weaponry and short burst of unstable flight through repulsion.
- wrist-mounted flame throwers, rocket propelled grenade
Less limitation on resources, more precise measurements allow for better Arc technology with higher energy output. Sustained flight attained and stabilized using boot and glove repulsors. More durable armor plating. Integration of home-computer AI. Max flight speeds between Mach 1 and 2.
- none beyond repulsors in hands, feet and chest RT.
Gold-titanium alloy used to prevent icing at high altitudes, maintains power-to-weight ratio of Mark II. Hot rod red added for aesthetic contrast.
Anti-tank missile, auto-targeting small caliber rounds, flares, repulsor tech.
After near-destruction of Mark III armor in battle with Iron Monger, Mark IV is created with easier removal functionality. Helmet can be removed entirely.
- Assumedly similar to Mark III
Suitcase Suit. Useful when Stark needs to suit up far from home or other appropriate location. Lighter and less armored, not built for sustained flight.
- repulsors in hands and chest RT
Advanced tech built after Stark invented a new element to replace Palladium and perfected his Arc reactor technology. Far higher energy output which we can assume allows for faster flight speeds (Mach 3-4) and more advanced weaponry.
- Sticky grenades, "one-off" beam and several other wrist and shoulder mounted weapons (used to intimidate Loki).
Rapid deployment armor that targets bracelet mounted beacons. Deployed after Mark VI sustains substantial damage while attempting to repair the Helicarrier.
- Beyond Mark VI weaponry: Auto-targeting rocket barrage, leg mounted missile compartments, back mounted jet packs for freedom of arm movement during flight.
Beyond Mark VII, we can assume Tony begins to produce armors for specific scenarios:
"Heartbreaker" Artillery Level RT Suit. Likely built as an anti-aircraft suit. Perhaps in response to the Chitauri "Leviathans" seen in The Avengers.
"Silver Centurion" Enhanced Energy Suit. Likely built as a prototype to test high energy weaponry or defenses (energy shielding etc.) Perhaps with the Tesseract in mind, its just more efficient use of the energy created by his chest Arc.
"Red Snapper" Disaster Rescue Suit. Built with telescopic/hydraulic arms to assist in rescue and retrieval of innocents during times of duress. Perhaps with Pepper or Coulson in mind.
"Igor" Heavy Lifting Suit. Built with Bruce Banner in mind, no doubt. Tony also refers to much "heavy lifting" being done during the construction of Stark Tower.
"Gemini" Sub Orbital Suit. Dreamed up after Tony's first venture into the cosmic unknown. Likely, boasts several life support systems including oxygen and temperature control. Also has back mounted jets.
"Shotgun" Hyper Velocity Suit. Assumedly the first suit to exceed Mach 8 (hypervelocity). Probably less impressive weaponry. Another one Stark dreamed up in an effort to keep those he loves safe.
Extremis armor? Telepathically linked to Stark for ease and immediacy of use.
And several other armors are pictured, but not yet named. See far left/far right: