As someone who has played a fair bit of 2k's carrer-mode and park mode over the past few years, let me make one thing abundantly clear:
WE DON'T WANT MULTIPLE GAMES HAPPENING IN A SINGLE INSTANCED SERVER LIKE NBA 2K'S PARK GAMES. THAT STUFF SUCKS.
It makes the game so incredibly laggy. Please just stick to the dedicated, one server for one game method. Seeing other games happening around you as you traverse a city is cool "in theory" but it's not cool in actuality. Actually, the whole "open-world city" thing is something that is cool in theory but is actually just a headache. I remember last year's 2k didn't even have FAST TRAVEL so you had to run/skateboard around the city with the terrible controls... even when playing offline games only...