Played about an hour last night with the default specifications. This was only because I just wanted to try it after the long 3 and a half hour download (59GB). The game was very smooth and visually clean. The rig is I5 quad core from a few years back, 12 gb ram, Geforce 770, SS hybrid drive for the game location and SSD for the OS drive.
I didn't start any missions last night. It was more of a run around the city for a while so I am not so sure how well the game performs when all the madness breaks loose.
The option to play first or third person was very welcome since a large portion of previous popular games have been FPS.
Not sure if the other GTA games had a gentlemens club, but I got to say it was a bit surprising how far the developers went. I got kicked out of the club from touching too much!