I wanted a high-power, neutral, lightweight speaker to put into my ported Thiele-style 1x12, which I use with a 200 watt Quilter ToneBlock 202.
EVM12L was too heavy, I hesitated between the Copperback and the Eminence EM12N, decided to risk the the Copperback, and I'm pleased with it. 20 hours of playing time and it's starting to break in really nicely. Clean, uncoloured, transparent; sounds great whether I'm playing 17th-century English folk songs fingerstyle , jazz, blues, punk rock - whatever. It just works, guitar sounds great, solid bass, sparkly clear treble, and no mud in-between, the Copperback just gives me the sound my fingers were trying to create. May be the "best" 12-inch driver Celestion has ever produced.