We're also debating between LP and James Hardie. I'd love opinions as well! The man at our building supply store raved about LP and said Hardie doesn't hold up as well.

My peanut gallery comment. What does the "guy" mean by hold up well?

It doesn't rot? The only thing that I am aware of with hardie is that it can break during handling. I have no idea if it is different for the other product.

I used hardie against the base of my greenhouse ( working greenhouse) after getting sick of replacing the wood every few years. It was literally up against the dirt for over five years when we sold the house. If looked new and I never had to repaint

After Googling Hardie siding problems I read some really interesting things about it. There's a class action lawsuit going on. Lots of paint peeling, mold, etc...The company is blaming the installers and is not standing up to their warranty.