I have one that has lasted a couple of weeks so far. I would guesstimate it's getting close to 100 ml and still works as good as new. I have had a dry/burnt taste twice, but it left as quick as it came.
I made one for my other Iatty yesterday which decided to short after about an hours use. My 1.5ohm atty was now about 0.5ohms and tasted burnt. My IMR battery kept up fine, but i wouldn't recommend
vaping at 25 watts

I wrapped a new coil and retorched the mesh-wick and it's been working fine since then.