No leaks what so ever. The fill valve works perfectly and with a pump and hold, it will fill the well of an RDA with some suck back when you release. When the container gets low it will take a couple of pumps to squonk though. There is no silicone bottle either, just one D shaped container that slides into the bottom.
The edge of the pump button could have been rounded a little to take the ugly sharp corner off but you won't hear Doug Marcaida saying "Your squonk button sir, it will cut."
I run a 30T in mine and charge it through the USB, I love the estimated time to full charge on the screen.
It has that 3 click to lock and 5 click to turn off foolishness, which will sometimes lock the mod when you turn it off and it will still be locked when you turn it back on again. That is just user fumble fingers error and not a hardware problem.