Yes! I bought OmniPAK to have all Xtra Styles after 11 (I already have 1....11) and the pro styles. I knew some of the VERY old music teaching programs and I have some limited interest. But I installed all the contents and I found lots of really good stuff, at least for me:
Songs and lessons PAKs, loops & riffs, instrumental studies, "modern" MIDI styles (normally released as bonus PAKs), fakebooks...

Now I understand better the different contents and the way they are released, it is not trivial.

Totally worth it for me to pay the extra for OmniPAK. Actually what I am enjoying now is the program and VST new features and the contents you mention because I'll receive the HDD in 1 week (so I cannot render anything in "Audiophile quality" yet).

Thanks for the tip.