The benefits of LiPo batteries are the smaller physical size and higer current output. Majority of LiPo batteries are physically size of a normal mini type battery but they last much more longer than NiMH batteries. Also there is no cool down effect in LiPo batteries such as NiMh batteries might have. This is best shown while NiMh batteries are running out of power, the rate of fire (rof) is going down and semi-shots tend to cause a jam. In LiPo batteries the power keeps the same all the time.
Another great benefit of the LiPo batteries are that they can be charged up with higher current without damaging the batteries. LiPo batteries do not need to run completely empty and should not either in order to re-charge them. In Finnish perspective, LiPo batteries work nicely on winter time too because the low temperature does not affect to the battery.
DO NOT USE YOUR LiPO BATTERY COMPLETELY EMPTY! Immediately when your rate of fire goes down, disconnect the battery from your gun and re-charge it. Re-charge the LiPo battery before storage. These guidelines will keep your LiPo battery in good shape. LiPo batteries do not discharge fast so you can easily then take your battery charged up into new game.
Use only LiPo battery charger to charge your LiPo batteries! Using regular charger will most likely damage your battery beyond repair and cause a fire hazzard.