I own two ProTanks, I found if you soak the tank in hot water for an hour before first use that funny taste should go away (removing carto first of coarse).
I didn't like the airy draw at first but in just a couple days of use I came to prefer it over tube cartos.
The flavor does seem lighter to me than tube cartos or a rebuildable, but the fact that I can cheaply and easily rebuild the head on these makes up for it, I prefer earthy dark flavors that seem to clog up tube cartos faster.
I don't care for the flavor of the silica wick (at all), but rebuilding with a bamboo wick solved that little problem.
I got a friend that got a ProTank, liked it well enough, but just preferred the tube cartos and switched back.
I think the bottom line is, we both like the flavor a little better from the tube cartos, but I like to tinker with my toys, he doesn't. It's all about personal preference I suppose.