While generalisations are generally unhelpful, I think it is correct to say that older WGs are more reliable than the young 'uns.
That said, I've had memorable punts with WGs Young and old. One gorgeous South American lass I've seen a few times, advertised her age as early 30's. Immaculate grooming, perfectly proportioned and toned petite figure and a pretty face; kinky as fuck and a great personality to boot.
She finally told me she was actually 43 and proudly showed me photos of her grandchild!
So, who cares? A good punt is a good punt, age notwithstanding.