Here's what I've learned in the past few weeks:
Alchem nicotine is ubiquitous now, incredibly pure, but recent batches are just totally off for my purposes when it comes to taste, smell, etc.
RTS was using them at least once. Draw your own conclusions about their rhetoric. What a pile of crap.
MFS first tried to rectify the situation, albeit with huge mistakes (ignoring me for weeks at a stretch, items "lost in the mail" (or were they shipped? I never got tracking...they ALWAYS send tracking))...and now finally I'm told that 'there is nothing wrong' as no one else has complained and so that's it. I replied and was ignored.
The bad news is I'm out 120$ and have to figure out a way to dump 5L+ of nicotine.
The good news is I just got 500ml from wizard and am very excited to test it out, break it down into smaller portions and round off my freezer supply of usable nicotine to one liter of good old WLR and 60 ml of vintage MFS.
Keep you all posted.