Why would you doubt it isn't true? Look at all of the other graphs by the blogger, nothing irregular usually happens if the crossover is well implemented.
I will post my impressions of both and I will say yes, it's there but it's not that easy to detect. I'll admit I couldn't really tell at first but when I went back to my HF3, something seemed sucked out of the Heirs, sounded too hollow in the midhighs when compared. Towards my last couple of days, I decided there was something very wrong in a specific region, though the 4ai was nice besides the error. When the graphs were finally posted, it was no surprise that error was there glad it was analyzed. I even know a user who's custom had that error (lucky for him he detected it right away)
Edited by Inks - 11/5/12 at 8:23pm