Ok guys so here goes - i know this thread is useless without pics, so i will get those up this weekend. In the meantime here are the results for some discussion:
2009 G37X with G37S coupe springs
The original height was about 4.5 - 5 fingers in the front and 4 fingers in the back (supergap) - with the springs installed it is now about 3.5 fingers in the front and 1.5 fingers in the back (so i got some of that droopy bum) I ordered some spring isolators to try and fix the rear a bit while i look for another solution for the springs that works perfect without any "fixes"
Took the car in for alignment - front is obviously within spec, the rear is sitting at -2.1 camber and thats as far as they can go...
When comparing the springs at the shop, both front and rear were exactly 1" lower than their X spring counterparts so it looks like the springrate in the rear springs is obviously not strong enough to keep up the rear (as the drop would have been even if they did)
I dont want to go with eibach's as i think they drop it too low for Chicago roads and I dont want to buy the front camber kit (im fine with purchasing just the rear tho) and i dont want to be at big negative camber.
Strangely it seems that even though the X's are supposedly heavier in the front, it negatively affects the rear (see Tanabe springs droopy bum on the X)
So thats about it.
And here are the pics!
Even though the drop is not that low in the back (compared to some other cars on here) you can see that the drop is uneven.
Here is the difference in the springs. These are the rear springs, the front ones were the exact same difference.
The right one is for the X and the left is the G37S coupe: