If I may, I would interject a couple of facts that seem to be overlooked with regard to this subject. The real relevance of the "Hemi head" design is not whether or not it is a perfect hemispherical shape. In point of fact, neither the Gen 1 nor Gen 2 combustion chambers were perfect hemispheres. What is important with all hemispherical type heads (of any make) is that it allows the designers to place the intake/exhaust centerline at 90 degrees to the crankshaft centerline instead of parallel to it. That is a feature that is unique to "Hemi" type heads. That places the intake valve directly on plane with the intake runner and of course, the exhaust valve on plane with the exhaust port. This valve placement is why all hemis have two rocker shafts per head. The real benefit of this, is that it reduces the amount of transition in both incoming and out going air mass. In other words, the radius of the port at the bowl is drastically less. I have a 6.1 Hemi, and those heads, CNC ported produce an intake flow at .600 lift of well over 360 CFM, while the exhaust is over 250. It is impossible to achieve those numbers in a conventional head with a "wedge" type chamber without radical port welding and port extensions on the exhaust side. I ran 340s for years, and those engines with professionally ported W2 heads didn't flow any where near those numbers. That is why these Gen 3 engines respond to headers and cams the way they do. So whether you want to argue that the modified chamber isn't hemispherical or not, just think of them as a TWIN ROCKER SHAFT engine. I don't think that would have the same marketing appeal to the public though. HEY HAS THAT THING GOT A TWIN ROCKER SHAFT ENGINE IN IT?" No, Chrysler has always done well with the Hemi marketing, and my experience with having owned a Gen 2, and now a Gen 3 has been very favorable. Gen 2 Hemis back in the day had a kind of bad reputation for engine failures, but it was largely because they reved like a small block, and were still pulling hard even when your brain was telling you to shift !!! LOL. No matter what else, the truth is like Ronnie Sox said one time in his South Carolina drawl, " Ya know, there's really only two kinds of people in this world; those who have a hemi, and those who want one". I think there's at least some truth there.
