[avionicsguy]

Actually from the link you provided, airspeed is absolutely a quantitative indicator of a stall.

"The airspeed indicator provides quantitative information about angle of attack, when the airspeed is not too low. Correction factors must be applied to correct for nonstandard weight and/or load factors.3"

[bbojan]

Absolutely quantitative except when airspeed is low, when weight is non-standard and when load factor is not 1.

I guess you and I disagree on the definition of "absolutely".