I'm not going to compare them to Josh's data, but I've got no problem comparing one S&V data set to another. Brent certainly didn't have a big problem making the comparison either in reading his writeup.
The PB1000
is significantly outperformed by the big Hsu down low. That's not liable to be the case with the bigger, costlier PB12+.
Looking at raw output alone, yes; of course, the numbers for the PB12 look very odd indeed, particularly the 5dB drop going from 50Hz to 63Hz.
Review: SVS PB12-NSD Subwoofer | Sound and Vision Magazine
Seems rather convenient to ditch the data when it doesn't agree with your positions, no?