ANR headsets
I use the A20 (sans Bluetooth) and although I agree they are pricey, I'm absolutely delighted with them. Flying a 172SP with glasses, I find the noise reduction and comfort excellent.
Can't directly compare them against the Zulu's or Sennheisers, but I do agree that Sennheiser generally make excellent audio kit. I have a pair of their ANR headphones I use on long flights as self-loading freight.
Rats404