Jup, Zippy's/Turnigy/Flightmax I never bought an other LiPo brand as the ones from Hobbycity so I don't know anything about the quality from the Flightpower/Hyperion/ThunderPower packs. They'll probably be better, but for the price of a LiPo from Flightpower etc. you can get 3 Hobbycity packs, so I'll stay with them for now.
I've seen many people using LiPo's for their E-Bike, they all seem quite happy with LiPo's.

Those 10Ah cells look awesome, but quite big

Someone at I thought RC-Groups also said these China ones are old used cells, but nobody knew that 100% for sure.