Ok got it!
This is just my preliminary review vaping on a genuine eGo battery with a Smoktech 1.7 single coil Carto. I will be vaping HC RY4 in the next few days on a homemade VV mod with a Boge Carto, Cisco 306 and a Ikenvape 3.5 Ohm Attie. If I have any liquid left over I will also try it on a Smokless Image Volt battery and Carto. Anything I've posted may change with time, please remember taste is subjective.
Pros: I Love Love Love the flavour! I like this HC RY4 variant of flavour over the Dekang flavour by ballparks! There's not so much of a creme brulee flavour with this RY4 and more of a mid note of Butter Caramel, seems to be the same butter caramel DIY flavour that HC sells. It doesn't have that low note of rubber I detect in some batches of Dekang RY4, so another plus for HC. Vapour production has been good, better then Dekang's.
Cons: There seems to be to much Aqua in this mixture for my personal liking. This is a problem I'm finding more and more lately with other non Dekang e-liquid from distributors in China. I wish it would stop as I find too much Aqua diminishes flavour on the pallet with steam and can singe my tongue with a Carto/PV setup that works for all other liquids. To much Aqua in the blend brings inconsistencies. The labeled 24mg strength seems to be a overstatement. I can normally over nic with a 24mg but can't with this. It's over 18 but not a 24. If Health Cabin's latest RY4 was my own DIY, I would replace all Aqua with VG and up the Flavour by 4-5%.
With so many RY4's on the market, most of them tasting almost the same, It's nice to see Health Cabin developing a variant that can stand out from the crowed. If the water content was removed and the flavour boosted a little this might become my go to RY4