I guess I would support the notion that for the average driver out there, the EPA vs real life mileage discrepancy will likely be greater in the PII than the HCHII. I think the IMA system is more transparent to drivers than the HSD.
That said, based on the GH mileage database, I am an average Prius driver, but I am quite a bit above the Honda test numbers. On my recent 2,200 mile road trip with a PriusII loaded to the gills, AC on all of the time, mostly highway (but some city) at around 70-75 miles per hour, including elevation changes to above 6,000 ft, I averaged 53 mpg.
That leads me to think that Honda drivers probably know more about the IMA and how to drive it properly for maximizing mileage, and less about the HSD. Either way, I think it is quite an accomplishment for Honda to come up with the numbers the HCHII can produce, whether it bests the PriusII or not.
I assume the above test is with a manual HCH, but it is never stated. I don't think it's quite a valid comparison to pit manual vs CVT, CVT vs CVT would be better. Now we need Toyota to run a similar side by side test, and then average out the results.
Either way, it's a very cool result, and my guess is over the next few (model) years Toyota and Honda will continue to leapfrog each other as new versions will come out.
Personally, I wish Honda would issue the fastback Civic as a hybrid.