I feel it's quite akin to Spoils (from Dark Ages)... Don't play it unless you need to. There is one contrast, and that is with Spoils, you don't play it and then buy Gold. Here, it seems like it could go either way.. the Gold helps out, but then would be cancelled out by the Curse, and then never again playing the CG.
Being able to get to some key cards, or key situations where timing counts would be what I've got. If Curses are helpful, like in Garden decks or with Quest out.
Of course, CG is pretty much a Gold again if the Curses are all gone.