Yep, it's insanely fast. Going between different buildings is so fast that the loading circle barely has time to appear. The longest load I've encountered is when entering the main world map, but it's still less than 2 seconds (short enough that the "film frame" image doesn't even have time to fill the screen before the area is loaded).
Based on videos, it's *MUCH* slower on the consoles. I'm glad they optimized this for the PC as a lot of console ports these days actually don't load much faster on the PC. UE3 games, for instance, receive virtually no increase in loading times over the console games and sometimes fare even worse. One example: Turok PC no longer streams data so you encounter load screens all the time AND each loading screen is several times longer than the initial load on the console version. That's just sloppy. Even in the case of stuff like Gears of War or Mass Effect, however, there is really no major improvement (other than lack of texture pop-in).