Been using Oneplus Bullets Z2 for mostly calls for more than a year now, and never had any complaints. Battery life is perfect, it just takes 30 minutes to charge fully and lasts around a week for me. Also the mic and speaker quality is just awesome. Bought 3 additional pairs for my family and everyone loves them. Also, one pair had some issues after 6 months of usage, so I took it to the warranty center and instantly they gave me a new pair.