Almost impossible to use with Bluetooth headphones if watch is on the left wrist. BT headphones have the receiver/antenna on the right side (AFAIK). Connections drops the minute left arms gets near the hip/waist or below. Tried with Bose, Plantronics and others.
My dead (waiting for new battery) Gear S2 maintained connection when worn on the left wrist without problem so this is a bit of a downer.
(I plan to do a full review of the watch asap)