If you have the new Z, you quickly realize that the stock seats do not sit very low.
If you're over 6 feet tall, you will quickly realize this especially once you put your helmet on. You have about 1.0" between the roof and the top of your helmet.
We installed a Recaro Profi SPG seat in our Z with Bride Type FG side mount rails, and instantly noticed how low the seat is mounted.  Like most cars, we started with the lowest mounting holes and the driver of the Z couldn't see over the dash.  He's 5'7" tall.  We then moved the seat to the very top mounting holes, and it was still lower then stock seats, but could finally see over the dash.  If you're under 5'7"  the FG Seat rails with the Bride Low max seats would probably not be the most ideal as you will have some visibility issues.