Knots always interests me. Short story, I still tie a double surgeon's as well. I hate blood knots, they are difficult FOR ME. There is a Dennison Blood knot tool, but bluntly never tried one. The popular nail knot tying tool called a "Tie-Fast" also can do a fairly simple double nail knot which in effect is similar but not a true blood knot.

Your line is going to break somewhere. Probably the best place to break is at the fly. You leave less tippet in the water this way. I still tie the DS because it is quick for me and good enough.

Here is a great article that I have in my favorites: http://www.midcurrent.com/articles/k...astlink_1.aspx