Tom,
The 10-12 minute sides bother me as well. I don't doubt it helps with SQ but think the larger factors (in regard to SQ) are how well they were mastered & pressed. Case in point... "The Golden Palominos OAO album" as well as "Calexico's Black Light album" are both >20 minutes per side & spectacular sounding. There are many others in my colection that fit that category as well. On the other hand, probably my best sounding album (SQ wise) is "The Butthole Surfers Widowmaker! EP", which is 45RPM / 12 minutes (approx.) per side, & the 45RPM Radiohead LP's seem to sound better than the 33's. So there is that...
Glad I could clear that up for Y'all 😀