Quension
Newly Enlightened
4sevens has stated before that the ratings they list are for the batteries they ship with -- a Duracell alkaline in this case.
Keep in mind the MiNis are using PWM, not lower drive currents.
No one's done a runtime test on low because it's not all that relevant - tiny differences in Vf/manufacturing cause big differences in runtime at low currents. If you had many copies of the Quark, you'd find a range of difference of roughly 20% in their low-mode runtimes. So whatever your final numbers are, they'll only serve as rough guidelines in regards to other Quarks..
Keep in mind the MiNis are using PWM, not lower drive currents.