I use Ex-Pro and Chilli Power batteries and they're just as good/bad as genuine NP-FW50s.
The charge duration doesn't mean much if you don't know the charge current. If the Sony charger is using half the current of the third-party one then it must charge for twice as long for the same effect. What does put me off third-party chargers is that they don't have the centre contact which I believe OEM chargers use to monitor the charge.