well considering I have Li-pos and run them in only a few cars for a couple of reasons, one is cost, and two is charge time about an hour or so. they sell smart stops for Li-pos but not for xmods ESCs, yet.
. a few of the things you have to worry about has been said but one thing and that is keeping the cells balanced during charging also, they get out of sinc and boom also.
you can buy packs with safe charge built in like mine have so its one less thing to worry about. here is the setup in my titan.
you will notice it is two720 Mah packs ran in series for a total of 1440 mah. this thing burns rubber with top speed gearing, 4WD and helimax on concrete. the only other one I run Li-po in is my monster truck, same setup as the other one but with torque gearing and no 4WD instead. both of them use the same electrifly charger. the packs cost about 25 to 35 bucks based on Mah which will be another factor with li-pos the more Mah the bigger the packs are.