Go ahead and get the Sackville - fine recording. You will be attracted to the side with Holland but spend some time with the other side. Rewards are wonderful things.
Great question.
I want to direct you to a chapter/intro to a wonderful book assembled by Frank Driggs and Harris Lewine called Black Beauty White Heat. This (mostly) photo book has an early entry about collectors/fans meeting Al Lion and Frank Wolff that is worth the price you have to pay. Find the book somewhere.
Change of era around the late '60s and '70s. Club owners and indie label owners inspired by the "post war boom" were retiring and selling out. Think about the "street" implications of this shift.
That being said, I think the newer "indies' and the cashing in by the majors more than made up for the difference. Just other people selling the records and making the money.
I may elaborate later.
I know this set has taken hits for sound in other threads but I think it is a "more than reasonable" representation of the recordings. I've had a few of them on 78 and the rest on lps since the late '50s.
My big complaint is Keepnews' deviation from chronology so he can lead off the set with "highlights". What a bozo.
Some of the later cuts are "fluff" but that is Diz with wonders and warts.
The earlier stuff is essential as is the best of the live material.
Not noted generally for the sound (but much of it is fine), the complete and ongoing nature of the label is the main attraction.
In spite of tons of opinions to the contrary, I prefer their Armstrong Hot 5s and 7s to JSP and Columbia/Sony.
A short rational (I hope) reason for short cds is they reflect lps recorded in a day when union rules dictated everything. Union contracts were written to reflect 3 hour sessions producing 15 minutes of material for issue. Any music (or session) longer required "over time" payments. During those days I always negotiated a deal for 3 sessions (9 hours in the studio) for 45 minutes of music whether that was the result or not.