I happened to have a friend's Persona B available to compare with my Dynaudio C1, which is much more neutral.
Interestingly, soundstage AV's measurements were right on. After running room correction both the scooped vocal range and the treble peak were corrected for.
My theory about the scooped vocals is that the floorstanders cross over at 450Hz, and the tweeter/midrange module was actually voiced with the X-PAL woofers in mind. By using the same drivers in the Persona B, they are missing quite a bit of output below 500Hz and they either insufficiently modified the 7" beryllium mid, or didn't make any changes to it at all, which leaves an output gap. Kind of a weird oversight for a $7000 bookshelf speaker, but it wouldn't be the first time there was a performance drop off with the surround channels in a flagship series (i.e., Ultima2 series).