wow hauling h2 in this fuel economy is just brutal. Anway......I've driven 6spd for my entire life and it never gets old. I love my Z stick, though I never tried 7spd.....I imagine it to be bit more comforable but less exciting. You get the extra spice out of the 6 spd imo. 7spd is like .1 second faster than 6spd in 0-60.
Ive tried nismo but there isnt much of a difference between nismo and 370 sport package. Nismo also has stiffer suspension so be ready for louder road noise and bumpier ride.
But I just love 6 spd. It doesnt get boring, having the privilage of controlling the clutch, and way more exciting than 7spd in everyway. The only paddle shift I'd get is if the car had a F1 transmission where the gear changes in less then a faction of a second.
Good luck with the decision