Re: What size bowl?
The funnel is a great bowl but frankly if you are concerned about shisha tobacco conservation I would either grab a mod, make one or stick to an Egyptian clay bowl. The vortex is a good option but takes more than a normal Egyptian bowl will to fill. It also is very deep and I have found that while people will complain about wasting the bottom layer of uncooked shisha tobacco in a funnel that problem still occurs in a vortex if using very wet tobacco. I still need to try Tangiers in a vortex bowl and see what I can do with that set up.