I use the 3366 frequently to tie all kinds of flies. Its a general hook that can be used for just about anything. From small to large Wooly buggers to simple hoppers and Chernobyl ants in the 10 to 6 size range. Great streamer hook in the mid range sizes and bigger bass bugs on the size 1 and up. Very reasonably priced hook that performs well for all kinds of flies. Its also great for spinning up prototypes because its so inexpensive, or using as a shank for articulated patterns by clipping off the bend.
Up/down turned hook eyes can change the look of the finished fly. But in practical purposes, a slight down turned eye (bend toward the hook point) can help flip a fly over (with the addition of a little weight like bead chain or dumbbell eyes) and ride hook point up. Used all the time when spinning a bonefish or carp style pattern, helping avoid snags somewhat. Patterns like the clouser minnow, crazy charlie, near-nuff crayfish, and the trouser worm can be helped by a slightly down turned hook eye.