No It's not the coils i get on with the rebuildable (even though its a bit on the small side for me)
and even some of the stock coils are very good.
I got TFV4s before the Crowns, was all I was using for a while,
got a few crowns, just fill 'em up easily from 50 ml glass steeping dripper bottles,
whereas with the TFV4s I had to first transfer from glass bottles to squeezy needle tip bottles to get the juice in that tiny (in comparison) slit in the silicone top.
I know it sounds lazy, but the ease (for me) of filling those crowns has spoiled me.
I know myself enough to know that I'll go back to my neglected TFV4s…
When I get myself some new glasses ;0)