I have had 2 of these 1300mah 4s packs for almost a month now, flown them on about 10 occasions for around 30 cycles total, and man do these things rip! Tons of power in theses packs and virtually no sag compared to other packs I have flown. I am flying these on an aggressive race quad with 2700kv motors and get 2:30 of hard aggressive racing. When taking it slow and cruising around, these are easily capable of 4-5 minute flight times. Even with these flight times I am still bringing the pack down around 3.7 volts per cell.