Originally Posted by Unknown Cyclist

I completely agree with you, however a cheap multimeter and an armchair do not an expert make. Science requires scientific principles and lots of those tests are woefully lacking. Collecting erroneous data proves nothing.

Using similar batteries in a WF-139 charger and doing the same with a 'superior' charger for an extended period of time and the same duty cycle, could provide evidence that the life expectancy of batteries charged in the WF-139 is lessened.

However, poorly conducted tests, inaccurate results and speculation prove very little. The OP asked for recommendations. I'm not saying that your recommendation is poor, it's likely that the charger you recommend is as good as the WF-139.

Is there any evidence that it is better ? Unfortunately not.

I'm not trying to pick an argument with you, it's up to the OP to decide what is good advice.