Compare launch title current gen games to recent current gen games; theres a huge difference. Then compare a modern next gen gaming system (a high end PC) to a modern console game. There is little difference beyond tessellation, higher res textures. The only thing the next console gen will bring will be that - plus initial support for 4k. That's hardware though, services is where next gen will shine.
No true at all. Game sizes aren't limited by the medium. Even games like Skyrim, Oblivion etc, don't take up a full DVD9 let alone a Bluray. PC exclusives have the option of being unlimited, but they're not.
It sort of is true (I work in console game development). New processes and techniques occur very late into console cycles. One thing Halo 4 did that previous games didn't was to process only what the player sees, where previously it would process around a radius and a long distance infront. All these little things to hammer out the last bit of performance. Uncharted 3 improves upon 2, Halo 4 looks better than Gears 2, etc.
If you want bleeding edge then get a PC. Console games are never about amazing graphics, their selling point is how easy it is to get into the game, about sitting back with a TV and exclusive titles.