Yup - build quality, state of charge, storage temperature and discharge rate apparently all affect the rate at which a Lithium ion battery will lose capacity. So my own strategy was to buy higher quality batteries with factory matched cells, and a capacity large enough that they can perform well with only a partial charge. That means I can expect to run them with less than a full charge for extended periods without deep discharging them, and that they'll still do the job even if they have lost capacity over a few years. Using an intelligent charger with cell balancing capabilities probably doesn't hurt either.

One thing I did learn from a lot of experience with different brands, grades, chemistries and capacities of rechargable AA and AAA cells is that 'quality' can be a relative thing. Short term performance is easy to accomplish. Predictable long term performance is almost always more expensive and never sets records for short term performance.

One option I picked when ordering batteries was the ability to 'link' batteries using a second interconnecting cable. Basicly that means I can double the capacity by clipping two packs together. Or in a few years still have the performance of one new pack by clipping two together. In the real world that means I can currently run 900 lumans for up to 18 hours continuously, or up to 5,400 lumens for up to 3 hours continuously, at my discretion. A twin battery pack fits nicely in a single water bottle cage.