I bought a Canon IXUS 950S bundle, which included a INOV8 replacement NB-5L battery, and must say that it doesn't seem to last half as long as the Canon one.
Maybe I got a bad one, but I think in future I will be buying the canon branded one's.
Oh and I am very happy with the camera, and it feels nice and solid and I wouldn't of wanted anything smaller.
I am also pleased with the photo's.