I have heard many Lubavitchers (generally from the older generation) speak about the importance of the Tehillim "Ohel Yosef Yitzchok" (OYY), the Tehillim printed by Kehot, the central Lubavitch publishing house. But not just any Tehillim printed by them under that name, but specifically the old, original print.
Kehot seemed to understand this "significance", because although they gave the Siddur Tehilas Hashem (TH) a makeover, changing the typeface and such, they didn't do so to the Tehillim OYY for many years. So even the recent clearer-printed Siddur THs have the old print Tehillim OYY in the back.
Kehot has only just recently released a clear print version of their Tehillim, which you can see here. Before that this was the staple; that's the one also that was printed in the back of their Hebrew siddurim, even the new clear print versions.
Below is a sample page of the old print Tehillim OYY. What was/is the "significance" of saying Tehillim from the old print OYY? I also remember reading comments which didn't have nice things to say about the new clear print version of the Tehillim on several Chabad sites. Why the old print?