I covered the issue in greater deal a few posts before yours (but came to the same conclusion.)

Alkalines start at 1.5 volts and go down from there. NiMH cells start at 1.4 volts and go down from there. (I'm not sure why they give initial voltages for primary cells and "typical" voltages for rechargeables, but it tends to lead to "apples to oranges" comparisons like this.)

This page gives some pretty typical discharge curves for both types of cells.

Ultimately, you won't get 3.75 WHrs out of your alkaline battery -- probably about 3.1 WHr instead at 100 mAh. As for your NiMH cell, you'll get about 3.2 WHr at at 200 mAh discharge rate (I don't have a 100 mAh discharge curve in front of me, but I'd expect a bit more power out of it then.)

Alkalines excel at low discharge rates and cases where they aren't used for months or years. NiMH cells excel at higher discharge rates and for their recharging ability, of course.

But you'll have to have a pretty high discharge rate to find NiMH cells delivering 4x as much energy as alkalines -- according to these charts, even at 2 amps the difference is only about a factor of two.

Agreed. But the claim made wasn't that they'd "lose out". Instead, the claim was "

*NiMH batteries, the good ones at least, have a capacity as much as 4 times a good Alky.*" That goes way beyond "losing out".

A more accurate assessment would be that the alkaline will beat the NiMH by a small amount for low discharge rates, and by a pretty significant amount for minuscule discharge rates (rates so low that the battery will last months -- like a smoke alarm.) The NiMH will win when the discharge rates are higher -- for example, it'll win by a factor of around two or three (depending on the exact battery) if the discharge rate is 2 amps for a AA battery.