I use Fine kit for most of the whites or blues I want to salvage. I was using disasembler 3BEK Kit when it was available, just because it had 250 uses. Will get more of these when they are available again.
Master of Black Lion for rares and exotics.
I got Journeyman's instead of Fine this past week for my standard (non-ecto-range) salvage and didn't see much difference in quality of materials. So it's back to Fine for me.