Thanks for all the advice/opinion.
My Avcomm's are nice and comfortable, but what started the question was that I was flying with a mate last week who was wearing a Sennheiser headset (I think) and I had to get the tower to repeat a couple of the calls, but he heard them perfectly.So it got me wondering.
I spoke to Adams today at Biggin. They can either send you the kit, or they'll do it for you.
So, I'll try the Adams route first and probably pick up another pair of headsets when I'm out in the States next year.
Cheers,
C23.