I have been using the dual coil cartomizers for about 2 months now...but can never seem to get more than 3 days from the cartomizer before it becomes severely airy and burnt tasting. they work great the first day and slowly getting worse. I know they are disposable but was hoping for a longer period before they need to be replaced. I vape about 3 to 5 ml a day. I get them full and refill often... so why do they get yucky so fast? What are others experiencing with dual coil cartomizers. I am using smoktek cartomizers.