Only downside to stocking up on batteries like that is factoring in the replacement cost every few years. Since lithium ion loose some of their life (10-20%) each year you have to plan to relace every 2-3. Most people replace their cell phones that often anyway though.
I standardize everything on AA except things like call phones that can't be found that way. I replace the AA's around the 80% mark and with good quality ones get 9-10 years use.