I've never had a blades deck and I've not heard much about them. I'll probably pass because I'm not familiar with them. I'm planning on getting the April Fool's deck and I'll be getting a couple more at that price!
What is special about the blades decks? and history/story behind 'em?
De'vo is big news in cardistry, or as he's prone to calling it, XCM (xtreme card manipulation). In the early days of cardistry, he states that cardists took a lot of flack from many magicians, derisively being called "jugglers" and words to that effect. He was one of the people that took the art out of the underground and brought it to center stage. He's also big into similar manipulations using knives.
The Blades decks were his way of combining his two favorite arts. They were specifically designed for XCM, and as such tended to be a little flashier than the average deck, though it handles nicely enough. Many considered his back designs to be WAY too busy, something that got toned down a bit in the Midnight Edition. And he doesn't care about the "Artifice factor", making some decks with full-bleed black backs and all-white fronts. This is logical, since his deck is for cardistry more than for magic.
One of the features I like about his decks are the faces, actually. He did something interesting, although short of a full custom job - all the black pips have a red line drawn around them, vice-versa for the red pips and the theme carried over into the court cards, colored only in white, black and red. I thought it was a nice visual touch.