SLS 2nd level have a shop called Unicell, seems quite reliable according to some of my friends who are regular DPs....but still after experiencing a few unreliable cells, I would prefer to have the peace of mind on using originals.
1) the sony chargers tend to give it a more reliable charge
2) the batt indicator seems to be more accurate in calculating the amp/hours & discharge rate.
I just hate it when it says 40mins left on the counter, but it dies off in a while....macham a live time-bomb waiting to go off without notification and instead of worrying about your shots, you're worrying about the batts.
In my work serving some broadcasters, there's definitely no room for unnecessary failures, not like some event or wedding coverage work where if you miss the footage, just don't put it in the edit.