Technology
While GTA IV was hailed as a crowning achievement in technology for the open-world genre with its expansive and detailed world, physics system and Euphoria, the game engine Rockstar North used was actually developed by Rockstar San Diego. The RAGE engine was originally built for Red Dead Redemption (and was shown off in tech-demo form at E3 in 2005), but has since found itself as the company's staple development architecture; evolving as needed to cater for anything being built within the collective Rockstar studios' walls. What this means, however, is that while the engine is available to everyone within Rockstar, the team who know it best are clearly the guys who built it. And all the while it was being tweaked and moulded to bring us GTA IV, San Diego were in development with Red Dead Redemption; learning from mistakes or shortcomings essentially tested with GTA IV. This shows in the final result; the game is very, very quick to load (so no annoying GTA IV pre-load art screens), and the game-world seamlessly renders in incredible scope. The only time you're really facing any lengthy loads is if you fast travel to different areas, otherwise it's all-immersive, never once pulling you out of suspended disbelief and your overall experience.
