The strongest NET I've vaped is Esoterica Penzance. I ration it as it's almost impossible to find now. Definitely in my top 5 for taste.
As far as commercial NETS go, that would be W2V's Paris.
Worst NET's IMHO are Confederate, ( yeah, I know, I know, must've got a bad batch ) it was dirty dish water. The other was a House Blend which I forget the maker.
My own extracts are the gunkiest bar none. The taste great and a coil change takes around a minute. Bring on the gunk!
Cold maceration is a definite no-no for cigar extracts in my book. I usually go 30% flavor ratio unless it's a Maduro or Oscuro, then it's 25%.
Just my