KGD only. Never tried silica and have used rayon once or twice but KGD is too easy to get precisely the right density 99% of the time, I trust that it's completely pure and it works wonderfully to hold juice in the coil for vaporization.
I have never asked for long life in my wicking but then again I use unflavored nic base and it doesn't gunk or carmelize. I easily get a week out if a wick and it can stand up to however long I pull at any resistance I've tried even at 1.5mm ID coil. I've never burned one although I have vaped them fairly dry on occasion, once or twice enough to taste it and I just rewet and go. Never burned one out.
I have never asked for long life in my wicking but then again I use unflavored nic base and it doesn't gunk or carmelize. I easily get a week out if a wick and it can stand up to however long I pull at any resistance I've tried even at 1.5mm ID coil. I've never burned one although I have vaped them fairly dry on occasion, once or twice enough to taste it and I just rewet and go. Never burned one out.