PC headsets generally provide a broader and flatter frequency response appropriate for high-fidelity sound. You should always try any headset before you buy. Single-or double earpiece. Depending on the application and individual user, there can be advantages and disadvantages to either. Single-earpiece models are generally lighter and easier to wear all day.
Most people favor one ear to the other.
Different headstraps, mic booms, breath shields, etc. Enormous variation here. Others surround your head with padded or unpadded straps and put a mic in front of your mouth. Swing-down booms and flexible booms are popular, though less sturdy. Foam breath shields inhibit breath noise.