As near as anyone can tell, MossyBacks are IMX graphite rods. It seems that Loomis has designated MossyBack as the IMX version of their "BCR" SPECIALTY RODS, e.g. Jig & Worm, Senko, Bass/Cast/Flip and Carolina Rig rods. It looks like marketing more than anything. These rods are sold as GLX and MossyBack only, there is no "IMX" version available. No need to compare the two, because you can't buy the same mossyback rod in an IMX and conversely you can't buy their traditional rods MagBass, SpinJig etc. in a mossyback. I think it is safe to say that Mossyback is IMX quality. JMHO
Ronnie