I was wondering if anyone could make a suggestion on a nail gun used for installing sheathing. I have been hammering in 6d nails that last two days and it already is getting old. I am not even 1/3 through the job. Plus I think new siding may be in my future...further justifying the nail gun. I have been considering this unit

http://www.amazon.com/Stanley-Bostit.../dp/B003SEGL6W

Any comments would be greatly appreciated.