I pretty much agree with what macfan57 had to say about this. TPO is definitely ROCK!
"The complete Blue Horizon sessions" box set is the smart buy for the blues stuff as you'd need to get that eventually anyways since there are many tracks on there that aren't available elsewhere so rather than buy those albums twice, you really are better saving up the 40 bucks or so and getting that box for the complete versions of those albums/sessions etc.
The only thing I repectfully disagree with is that there is still much great PG stuff to get beyond TPO and the CBHS box like the rocking "Live in Boston (vols. 1-3)", "The vaudeville years", "Show biz blues" etc. etc. etc.
John