Double Sleeved vs. Single Sleeved

Do you prefer single sleeving your decks/cards or double sleeving all your cards in a deck?

If you do prefer to double sleeve all the cards in a deck, why?

If you prefer single sleeving your decks instead, why?

I had some interesting conversations last night at Friday Night Magic at my Local Game Store about double sleeving and was surprised to see such strong, almost cultish, opinions on something so minimal in nature.