My sense is that Costco batteries generally last longer than other batteries I’ve tried, so I consider them good value.
EXCEPT that I sometimes have the frustration of new batteries dying right away. Once in a great while, it’s within minutes. More often, I will find the battery level severely reduced (as low as 50 or 60% of capacity) within an hour or two. Sometimes they register at 90% capacity as soon as I put them in. I haven’t been able to track any consistent reason – it does not coincide with activities like streaming. They are always years within the sell-by date. I sometimes wonder if something is going on with my HAs (Oticon OPN1) that draws them down.
It happens frequently enough that I never go out without a near-to-full pack of batteries. If I have to replace one, I can’t be sure that it will last a few hours, let alone the rest of the day.