Conranch's JV hackle is some of the best soft hackle feather money can buy. Tying a proper soft hackle collar can be part of the issue with how they perform, too. You have to get the collar firmly flared from both behind and in front of it. This can be done with thread, a bit of material, etc., but getting the barbules flared away from the hook shank to where they will remain flared when the most gently stroked by a bodkin, etc. is the objective. This will prevent them from plastering down to the sides of the fly too readily, too.