I tried KBV on 4 different cartos of various "ohm-age" -- V4L CoolCartos, V4L Premium/Wow Cartos, CE2 Clearomizers (3.0 - 3.2) and IKV's mega 808s -- and at various voltages (3.2v - 4.5v) with each one. I was unable to get a good flavor from 2 of the 4 I ordered although they all had a very pronounced and yummy "nose" when opening the bottles (with the exception of Peach Melba, it smelled like stinky feet, and tasted like stinky feet smell, eww...and Auntie Ms Coffee tasted like burnt, "left-over from night shift" hospital coffee).
The juices I had (OMG, Caramel Capp, Auntie M's Coffee and Peach Melba) were all their standard flavoring at their standard ratio of 60/40. The juice was quite thick, thicker than others I've had at the same ratio, and I had wicking difficulties in all the cartos.
I re-tried them a month later and noted no appreciable improvement. The Peach Melba was still strong with Eau de Toe; the Auntie M's Coffee still tasted old and burnt; the OMG was just a tease of sweet nothingness and the Caramel Capp just wasn't there - no caramel, no cappucino (although I readily admit this particular juice smells absolutely divine and was the most disappointing because of just that).
I would like to commend KBV for very good service, for fast shipping, a surprise sample and a very pleasant and personalized thank-you note. Their "joose" is just not for me. Like Ms. Ocean said, "I know alot of folks really love this vendors juices, just not me. Thank goodness we vapers have such a large variety of vendors to choose from" -- +1 to that.