Hi G Henslee:
I concurr with your assessment of the James Hardie product. I was
actually referring to 1/2" Hardibacker in my previous post. I, too
have used other products, like Durock, and found them more fragile and
more difficult to work with, though only marginally so.
When I recently rebuilt my tile shower because of a faulty shower pan,
I found sheets of 1/2" Durock behind the wall tile (thank goodness it
wasn't greenboard!). It had been nailed to the studs with roofing
nails, but many of them were loose, allowing the tile backer and tiles
to pull away from the wall a bit. This caused no cosmetic issues, but
still convinced me that roofing nails are inferior to screws when
fastening something that should last for decades. Of course, if you're
bonding the backer to the subfloor, it probably doesn't really matter
as the thinset or mastic will do most of the work.