I went with a yiloong predator mech from 3f, switched to a yftk 8.5ml soft bottle and spread the contacts a little for the 20700; it's been working quite nicely. I also have a pulse bf on order, due to ship the 15th; I expect that'll be close to actual shipping date, one known update they're making ( an alternate part for the off switch). Best price I'm seeing on the pulse right now is $32 shipped from vapesourcing.