i was facing the same decision last year.. a speedy or a ribera.
i ended up picking the ribera and i am so glad i did!! shes so sturdy and she never loses her shape. i always get complimented on it too, because its just not a bag you see very often... unlike the speedy.
so if you want a bag that will look the same in 50 years, canvas and 'vachetta' wise.. id go with the ribera!!!