I use cordless tools every day and the Panasonic 15. 6 3. 5Ah is my all time favorite tool. It has the best ballance, feel and weight. The battery charge will last at least twice as long than any other battery on the market. I have no experience with the newest Li-Ion batteries, seems Makita's newest 18v drill is amazing. For pure power and torque I use the tried and true german Metabo 15. 6 hammerdrill. It has more torque than Bosch 24V drill. I also own Bosch 14. 4 and 18v drills. They boyh are very well made units, exept battery charge last short time. So the Panasonic I still rate as my#1 choice. It charges the battery in 15 min.