personally i don't care if a rapper really was a "gangsta" or not as long as the music is good. they could be from art school for all i care.
only very rarely will their backround matter.
an example of when backround matters:
rick ross i won't listen to because
A: he's a cop
B: he stole his name from one of the greatest hustlers of all time, freeway ricky ross.
2nd Jeezy. If you bottled up the sweat from his balls and sold it as cologne, the people who bought it would attract more bad bitched like Nicki Minaj, hoes who don't trip and pay the bail.