Insanely late here.
Had an 06 s tune that had everything but the cold air intake and header.
Had a 2.5" to 3" nismo exhaust, an I had a 2j racing Medusa v2 long tube header I never got around to installing.
I took very good care of the car while I had it, and in ideal condition it would Dino between 190whp to 205/10whp.
I was the third owner and don't know if the previous owners had put a tune or something on it, but it was definitely a bit more powerful than the non optioned out spec v. That was with a box air intake and the stock pre-cat exhaust manifold.
Can only assume it would have been making more power if it had the cams, cold air intake, and if I'd installed the header.
Again, there is a chance that a previous owner had gotten it a more aggressive tune, because I got pretty bad gas mileage, around 18-22mpg.
All in all, I'm pretty confident in assuming the S/R tune produce at least a little more power.
They definitely handle much better with the tighter suspension, bushings, sway bar, strut bar, etc., and the brembo brake kit.
I got lucky, and the original owner spent some money on optioning it out. Being in and seeing other se r and spec v, there's definitely a noticeable difference.