Hello out there! Just put together my first DC tank on a VK XL manual using Wow juice in the same flavor as in the cartos I first tried from a sampler pack. The flavor in the first carto was smooth and if you will, kinda buttery...very pleasant. When using the same flavor from the 30 ml bottle in the tank on the VK manual, the taste had a harsh bite, not at all pleasant like the first carto. I'm sure the tank carto is not burnt. I'd like to try more flavors but the dilemma is if there is such as difference in taste how do I trust trying new flavors then going on for the 30 ml bottles and running into the same thing? Is it normal for the juice in the bottles to be different in taste? They were both in the same mg of nicotine and used on the same device. The flavor was Vanilla Shake. Any help is appreciated. Thanks!!