I have a Rhino 4s 4900mah pack, it's been great so far. It has maybe 15 cycles on it, and always is well balanced. The pack is a bit long, but that's not an issue here.
These 4900mah cells have single tabs on opposite sides of the cell, like the current higher discharge cells out there.
Good info Metalman. I wonder if they are knock offs, or rebranded cells?