(Necro or not... FYI)
My GTR also has terrible lag when hitting the gas from a slow roll.
I find myself thinking/yelling "GO GO GO GO GO WTF" whenever I quick stop and try to go again right away.
It sits there jerking off in 2nd (or even 3rd).
Believe me, a 2nd/3rd gear sub-10mph start with 0 boost and 4000 lbs, is just plain painful.
I've learned to just say "F it" and wait if there's any traffic coming - even at distances where I'd feel safe pulling out in my old 93' accord.
If I'm in a hurry, I'll make sure to switch to manual and pre-shift to 1st before I stop.
Which is fine - if I can get to 1st before I stop.
Switching from 6th to 1st generally takes longer than it takes to stop - if you're stopping quickly (not slamming the brake, just a basic quick stop).