well, if one cost 2 times the price of the other one, and have the same benefits, i think there's no much discussion which one to get
in my opinion, and with my small knowledge in electronics, devices like this that uses higher voltages are "inherently better", cause they use lower currents and have less "components stress", because if you use lower voltage/high current, the components have to be higher grade, and they generate higher heat, shortening lifespan.
so this battery packs that use lithium, or other batteries with higher voltages (11.1v for example), are more likely to work well for a long time than the standards "AA battery" ones, in result, more unlikely you get a bad one or one that goes bad quickly.
li-ion/lipo are rated between 300 to 500 cycles. the cycle life is calculated till the battery holds about 80% of the original capacity. can last less or more depending on user operation. keeping them fully-charged always, reduces lifetime. discharging them till empty reduces lifetime. too hot environments reduce lifetime, etc...
just make sure you get from a brand that sell spare batteries and get the cheaper one