Hello Doug,
Ah yes, the cell balancing issue...
The RC people have found that if you push a battery pack to (and beyond) its limits, the individual cells become imbalanced. However, using the pack well within its charge and discharge limits finds the cells staying very closely balanced. I have not seen test results for lead acid batteries, but this trend seems to hold for NiCd, NiMh, Li-Ion, and Li-Poly batteries.
The 1.75 volts per cell is listed as 100% fully discharged at 75 F. I have no idea where the Schulze people came up with their information on the damage at 1.7 volts per cell, but sometimes meanings are lost in the German to English translation. At any rate, discharging below 100% DOD always produces problems.
I agree that it is a lot safer to limit the discharge to 2.0 volts per cell.
Thank you for the reminder on the influence of temperature on voltage measurements on lead acid batteries. That detail had slipped my mind and the temperature effects can be significant.
Tom