First of all, neither are TSO'd.
I bought Mach 1's when they first came out. They had a lot of feedback from the A/C current running through the windshield heat. Lightspeed took them back and modified them. When I got them back, the mic didn't work at all. So I gave up and sent them back for a full refund. I used them for 2 trips and didn't like them. Always tangled. They don't block out a lot of noise. I'm convinced that noise vibrations travelled right through the earplugs and directly into my ear.
Next I bought a plantronics with a custom ear mold and a splitter to have it in both ears. Hated it. Sounded like everyone was in a hollow tube. My voice clarity was terrible. Everyone had a hard time understanding me. To hear other crewmembers over the microphone feedback, I had to turn the volume up too loud to the point it hurt my ears. I'd bet that these will damage your hearing over time.
I was not impressed with "in the ear" headsets. I now use entry level noise-cancelling headsets. The cockpit is so much quieter now, I hear things that I used to never hear before.
Hope this helps on the Mach 1.