Pretty much a useless addition to a car, its only purpose being looks, the lambo hinge adds quite a bit of weight, the automatic version would add weight like there is no tommorow, fantastic if your building a showcar, and will look great for you ajnsx especially with all the other parts you have added to the car.
From knowledge of lambo style door kits for the 300zx, they add 17 Kgs (ahh 37 pounds, unknown for the NSX kit) while an automatic sissor door for a Mustang added about 45 Kg's (99 pounds, again unknown for an NSX kit) to give rough guides, and the door opens pretty damn slowly, again another show thing
I am waiting on the weight of the Veilside fortune kit, according to the veilside rep here, it will dramatically reduce the weight of the NSX, if it truly does It will be a definate for me, the wild look of the Kit far exceeds the look of a door mod on a standard kit, and functional too.