i would prefer 2x the benefit which was another idea that was floated. Problem is even if u have 7 slots available. there is only so many perception gild thingies. you will never reach what the cape did before. however if it benefits its primary stat 2x, that would be nice.
Two slots isn't a good solution because you can't stack the same gilding on an item, making two single slot items better. What they could do is either provide some base stats on two slot items, or provide a multiplier for gildings on them.