Depends... if you already have an H-class ticket or need to buy one for some reason other than the upgrade, I'd go for the upgrade unless you plan on using your miles for something else. (I don't believe in mile-hoarding... use them while you can.)

If you have to buy H-class instead of W or V just for the upgrade, it's probably not worth it if you're flying from ORD or the east coast. On a non-stop flight from the west coast I would upgrade though, unless the fare difference was too steep.

andy