So, I picked up my copy at about half eight yesterday morning and played it almost continuously for 12 hours
Im really impressed, its a huge upgrade on 4 imo, the car handling has improved, the npc dynamics and not to mention the graphics (no more stupid looking unrealistic faces)
There are some glitches here and there but nowhere near enough to spoil the game itself.
Finished my first heist last night, I love the multiple options the game gives the player to see out each job.
Also, as somebody mentioned previously, the three character element is completely justified. They've tied it altogether so well.
Trevor is easily the best character, even the faces he pulls when he's standing idle are hilarious
10/10 for me.