A few things that itrest me.
A quick menu can be called up to switch characters, the camera pulls away into a Google Earth-style vantage point and then drops into wherever the chosen character is
Rockstar's playtester pours a trail of gas away from a vehicle and drops a zippo lighter on it, the flame travels back and causes a huge explosion
Each character has his own personality motivation and skillset
They go about their daily business when you're not in control, so you might find them in surprising situations when you take control of them again
I love how you can change to a different character mid mission and play their side of it.
You can stay as Michael and try and pick of the enemies or select franklin, switch to his perspective and snipe them from afar.
Sounds **** amazing.