Okay, so I don't wanna sound better than thou or anything.. but why would my load blow quicker with a Pornstar.. than with a regular girl? Because a pornstar is meant to be hotter/better?
If anything, I think I'd go longer with a pornstar - just because after starting, I'd mid-way through start to think how many other dicks have fucked this shit, then start to lose a bit of hardness, then hear a moan or feel a random unknown tongue in my ass (because pornstars have that ability, to tongue you in the ass from no where) and get hard again, then start to question if this bitch has an STD and lose a bit of hardness, followed by a question of uncertainty if I should just pull out now, or not, then notice her begin to squirt everywhere and get hard again and finish up... with a trip to the Doctor, first thing in the morning, to make sure my shit hadn't been destroyed.
So.. what I'm saying is.. probably just as long as with anyone else, because a pussy is a pussy.. except for one thats been fucked a thousand times. Then its a small canyon.