Every knot has advantages and disadvantages. The blood knot is small and compact, and the ends come out opposite each other, not cocked off at an angle. So it's ideal for connecting MOST sections of a knotted leader. The blood knot is simple, although learning to tie it without a lot of wasted line on the tag ends takes some practice. It's not as strong as some other knots, percentage-wise. That's not a problem if you're connecting 15- and 12-lb. sections of a leader that is going to end in 5-lb test tippet. I build leaders with blood knot connections, except the knot between the tippet and the next section up, for which I use a uni-knot, which is much stronger.
The perfection loop knot is similar: compact, easy to learn, and comes out straight. It's not as strong as a double surgeon's loop, but it doesn't have to be.
The double surgeon's knot is one of the strongest, and easy enough to be tied by feel. It does waste some material, and cocks off at an angle. But for replacing a tippet in the twilight, during a heavy hatch, it's a great choice.