For general coin shooting I like the Etrac. Strengths are it's very stable and accurate ID & unmistakable tone on deep silver. Weaknesses are weight and recovery speed. Requires a slow sweep speed and is not as sensitive to tiny low conductors.
For relic hunting or eeking out the last few coins from a trashy/heavily hunted site, I'd choose the Equinox. Strengths are that its very fast, waterproof, lightweight, and has no trouble what-so-ever hitting tiny low conductors. The Nox is better suited for picking out tough targets from trashy sites. Hits coins on edge like a boss. Weaknesses is that the ID can be a bit jumpy and the depth meter leaves a LOT to be desired. I don't know if they've fixed it on newer models but the shaft on mine developed some wobble. I replaced it with a plugger shaft, which solved the problem.
All just my opinion. YMMV.