It comes down to individual pref. A third party battery might usually comes in a higher capacity and cost a lot less. Third party does not actually claim to be original anyway, thus cannot truly be considered fake or imitation, but just a replacement battery alternatives.....like AA Energizer or AA Duracell (same size, different brand).
Performance and reliability wise will depend on brand quality....even original sometimes fails.
Anyway it is never recommended to leave battery in the camera if not using over prolong time....original or not, hence minimising leakage problem. So for me I''m nuetral....