Compatibility
The compatibiltiy issue has been covered before. Something to do with microphone impedance differences. Do a search when it comes back.
Regarding Peltors I had a pair and loved them. If found they were compatible with any headset except a DC. But since every instrutcor I flew with used DCs they always blamed the peltor.
I gave up in the end and bought a set of DC 13.4ANRs which are excellent.