As promised to Alfonso, here is my Mamm. candida, this is the pink spined form formerly known as Mamm. ortiz-rubiona, it's approx. 20 years old. I killed my white spined one years ago. :(
I love the dense spination on this plant... It's been a slow grower, but it's quite happy, I expect some buds to start forming soon. Will post another pic when it flowers.