I can't add counter-arguments because we are talking about completely different things. If you read their article, you will see that it says that most prefab *houses* are still using the same insulation system as stick-built. I said prefab *panels*, which are a different technology.
I thought I pretty clearly said that I am talking about relative energy efficiency *not* cost. If you are generating electricity by burning coal, then the state standards that you mention are just fine. If all you care about is cost; just turn the thermostat up and down as needed like Al Gore. Also, insulation 'experts' are usually interested in selling their particular technology, and there aren't any insulation experts that sell prefab panels and wall systems.
I hardly consider where I live Arctic---I've lived in the Lake Effect zone, and winter camped in the mountains for years never using a tent. This is my version of living in Florida.
Again, air leakage around openings is the result of shoddy construction, not design. See below.
But it is the opinion of physics. If you build two identical houses, and one has R19 effective walls and one has R30, you will lose and gain heat at different rates. I have the luxury (heuristic, if not economic) of moving between 3 space on a daily basis, one of which is poorly sealed R7, one at R19 well constructed, and one at R30 well constructed. Today, because of our conversation, I confirmed the test I've done in the past---placing the palm of my hand on the wall of the different spaces. In the first case, your palm starts and stays cold, in the R30 it is just neutral, and the R19 starts cold and ends up feeling slightly cool after about 15 seconds. What's interesting is that the R30 air temp is about 52 while the R7 and R19 are around 58. Outside temp is just under 40.