Having tried multitude of headsets, here are my two cents:
- Bose A20 is a good headset, but price/performance ratio is IMO poor. It is just too expensive. Though you may use it as hi-fi headset for listening to music at home :-)
- With passive headset you don’t have to take care of carrying spare batteries for ANR function. Bose A20 is bearable but no good in passive mode.
- My first ever headset Sennheiser HME 100 provides absolutely great price/performance ratio. Those massive domes really give very good hearing protection and audio quality is high. I still occasionally prefer HME 100 over Bose A20 to be honest. I tried quite a few other passive headsets, old and new, but nothing topped Sennheiser HME for me yet.