On day three here. I tried the silver (RY4) on my 5V box mod and I am getting a burnt taste. The BB Menthol on the other hand is performing well at 5V (no detectable burnt taste). As reported elsewhere, I believe it is the liquid I am using (RY4) and not the carto itself although "the look" is experiencing the same issue with her silver one. I don't know? I may change up my liquids for future
reviews if the situation arises.
What needs to be said here is that although these were developed for HV
vaping, they perform extremely well on the eGo and at 3.7V. Therefore, because of their design folks may not need to go HV with them to find HV satisfaction, but can indeed remain at lower voltages because they do render a 5V vape at lower voltages without the heat associated with HV voltage. In my experience anyway.
The silver carto performs like a champ although I still cannot use it over 3.7V. It is seasoning very well and has tightened up just a wee bit

(read I mean a wee bit). TH has diminished to 2 to 2.5 however with seasoning. Flavour has not changed neither has vapour production.
The black with the BB menthol is performing well at 5V and the numbers have not changed perse but the vapour produced is warmer and to be expected.
It is my recommendation that these cartos be acclimatised to
vaping at 3.7V for a day or two before graduating to 5V or higher. IMHO the dividends far outweigh the harshness of a fresh carto.