How they fit, are they set up correctly, what are the features, how do they perform, do they need adjustments, how should the different programs be set up, am I understanding speech better, how long until my brain completely adjusts. Those are things to be concerned about, not whether you get 3 days, or 5 days or a week out of a battery.
See froggy above. If you got 3.5 days it would be $47 a year. So all the big differences in battery use mean that batteries will cost somewhere between $23 and $47 a year.
I stash batteries everywhere including my car, so I’m never without batteries and I know about how long they last so I will go ahead and change them if I suspect it is close and I’m going to be in a situation where I don’t want dead batteries to be an issue. I get 3.5 to 4.5 days.