I bought the Lightspeed Mach 1 and didn't like it. It easily falls out (even if just partially) by tugging on the cable. Very likely it works better with custom-moulded earplugs (some US pilots have reported as much) but with the standard ones it was useless for serious use.
I would be OK for passengers, especially female ones that don't like their hair messed up
Nothing beats the Bose X, which I've had for 5 years now, for performance and comfort on 6hr flights. Their only drawback (apart from possibly the cost) is that they are not built like a tank so not suitable for club/shared use, and you have to brief passengers that these things do NOT cost £20 so they need to take care of them. I do the "headset briefing" along the briefings on the liferaft, the EPIRB, lifejackets, etc.