Well now, I didn't say 65% or lower, I said 70%. I'd prefer higher, but again, the point is to have a reliable process, not to show off a number.

And respectfully, I doubt you get 92% mash efficiency*. Most homebrewers don't rigorously follow the calculations:

http://braukaiser.com/documents/efficiency_calculator.xls
...and again, that's still okay. because it's about consistency, not a specific number.

*Let's say I have 2 kg of grain and 13 L of water in my mash. Let's say that I achieve 100% conversion efficiency, which I will not, but it illustrates my point. I will still have 0.75 L/kg (0.09 gal/lb) absorbed by the grain and not recovered. So that's 1.5 L of wort not recovered. 11.5/13 = 88.5% mash efficiency. To get 92% you'd need to have 100% conversion and about 0.06 gal/lb absorption.