If your price point is out of range of the Zulu and Bose, the Telex Stratus 30XT ANR (up to 16 dB) headset can be had for nearly half the price of the others and works just fine and with pretty much the same features. One unique aspect is that the volume adjustment is via knobs on each earphone instead.
I have been a David Clark fan many years. I use the Lightspeed Zulu headsets now however. We have 2 in each of our aircraft. Nice comfy fit. I prefer the fit/feel better than the competitors product, Bose.
There is NO question which headset to invest your $$$ in... the Lightspeed ZULU!
I have many different headsets now all gathering dust in the closet... been using Zulu's since inception... from gyrocopters to jets, hands-down the best headset... hours of comfortable use, great ANR, and bluetooth that works great. Top all that with a company that stands behind them 100%... you can't go wrong!
Our flight dept likes the Lightspeed Zulu best overall. Personally, I like the larger ear muffs vs the Bose. Quiet...pretty much the same. I advise you to get either the Zulu or Bose electric noise cancelling models. Anything else and you will only wish you had spent a little more and got something which will protect your hearing better. I have a David Clark in pax compartment for intercom use. Is not electric noise cancelling, but I did my own noise cancel system which is near same as Oregon Aero sell for $30. Unscrew the speaker from inside the earcups and stuff soft foam all around it. Do no screw it back to cup, but leave it float loose. That did help a lot but sure not as quiet as the electric headsets. I use the rechargeable AA batteries and they seem to last as good as new ones. Recharge takes about 10 hours on those batteries. You can pack the unit around, not too large, or leave it at the house. Keep a half dozen spares with you however. I have been a David Clark user many years, but their electric headset is not near as good as the Zulu or Bose.