How much of a pain is it to install sheetrock?

Not bad, as long as your aren't hanging the ceiling.

Hanging sheetrock is easy. Floating it is where skill is needed.

It is a pain in the arse.. The following happened to me. Fortunately it was a small area and located in a bedroom closet.

You may have done this already.. But if not, you need to make sure you don't have any mold anywhere before installing the Sheetrock.

not that hard i just finished up the sheetrock work in my new addition. It is heavy but the initial installation isn't bad it is the taping, mudding, sanding and texture work that is tedious and a dirty mess. I would also suggest that you lay out a grid on the gypsum boards before you hang them in place it make screwing them to the wall quicker. I was installing over solid plywood sheeting so it went pretty quick.

Hanging is fairly straight forward - it's floating and taping that are more labor intensive and difficult - akin to the difference between pouring and finishing concrete (although not as extreme a difference).

I pay $.25/Sf for hang, finish, texture. So I wouldn't consider touching the 1st sheet