I'd rather have a week in South Carolina, b/c of the historical sights of the state.
I just spent a week in ID and there was history a plenty as well as great recreational opportunities. That's not to dismiss SC, but I'm not sure why you think there are no historical sights in ID.
Oh, there is historical sights in ID. But I think SC's are better.
Other than historical Charleston they are fairly equivalent from my visits. The places are different in type, Revolutionary and Civil War sites vs exploration camps, mining towns and Indian battlefields but both cover a lot of the same period from the Revolution (or just after with Lewis and Clark for ID) through the the 1800's. I'll grant that there isn't anything in ID that compares to Charleston. Is there something else I'm missing or is just about Charleston?