For the record I have 6 x 6S 30C turnigys, they are nearly 2 years old, I still get the same performance as I did from new, I have only charged to 4.1V and with one exception

have always stopped at 3.3-3.4V per cell, batteries running 2 parallel mainly then 3 parallel for longer runs, I am pretty sure I will see another couple of years at this rate, they get charged 3 full cycles every week, although the norm is to charge at 50% capacity with the occasional 80% drain at the weekends.
You simply cant get better bang for your bucks, light, very powerful, super long life, cheap, easily available, as long as you manage them properly they are safe too

I think if I were ordering a bomber or a fighter I would ask if I could have it without the battery and the charger.