I used them this past spring for the first and only time. Yes, I about cr@pped when I saw how much they were especially prepainted and I over ordered about 3/4 square

. Coming in that large of panel I imagine they go up fairly quikley in the open areas, the job we did it was used in small accent areas and a dormer. If I rememeber right you can free nail if you have ply or osb sheathing.
Hardie has a good service program and will come out to the job site for "lessons" on installing. If you get them out make sure to ask for some hardie blades, he was pretty generous to us but then again we had 100 sheets of 4 x 10 hardpanel too.