Playing through now, I know the plot already so your ineffectual spoiler warning doesn't really affect me.
When I have to make the choice, I'm saving Dwayne. Playboy is an asshole. He's just a grubby little dealer who was fortunate enough to move up with his friends' help, only to abandon them. Dwayne lost it all. He was just like Niko. I'd rather save Dwayne than Playboy. Playboy was a punk. He didn't deserve to live after ordering the death of his former mentor, the man who got him to where he was. Plus, I'd have killed Playboy myself if the storyline didn't tell you to, just to have his apartment.
"Don't f*ck up the [construction] site too bad!" I'm sorry, would you like to come down here and kill a couple dozen guys without causing the tiniest bit of collateral damage?