I know Nate uses a Quarq power meter on his MTB and used to have an SRM. Chad has a Quarq and Jonathan uses either a Quarq or a Stages. The Stages power meters are crank based while the Quarqs and SRMs are chain ring based. These power meters do not take more beating on the trails than when they are used on the road unless the bike goes tumbling and the power meter hits a rock or something. That said, this still isn’t any different than if a road bike hits the ground.