Sometimes the goldens disenchant for more then it costs to make the regular cards, in that case I'd disenchant as the goldens make no difference in a deck. If it's an even trade then I would just keep the golden. I wouldn't disenchant any other cards just because the conversion is so bad, you're generally better off just doing arenas and slowly building up a good deck from cards found and dust earned for constructed (or buying a big set of packs).