1. Is the heart a solid piece with ports, open chamber, or open chamber with cover plate for ports?
Traditional Style heart, solid with ports.
2. Is the hose port wide bored? How well does a Razan hose tip fit into it? (I've read it's pretty small so the fit of the Razan is a concern)
The port is pretty small, but i have gotten a Nammor/Razan in there.
3. How is the purge compared to a KM?
4. Is the draw slightly restrictive or is it more like a KM?
Open like a KM.
5. Have they fixed the short down tube issue?
It's easily the best hookah on the market.