Flesh Versus Steel: Both have their partisans within the Eldraeverse – many branches of the Silicate Tree are steel fundamentalists, although how much of that is rationalized hatred of their organic creator-enslavers is open to question, and they’re not the only ones. Likewise, there are partisans of the purity of the flesh, like the purist Gardeners of Rechesh (who have endless trouble trying to build organic-tech spacecraft, etc.) and more moderate, tool-accepting groups.
The Imperials, contrariwise, would point out that choosing one above the other is to pointlessly limit yourself. Of course, since the average Imperial is wandering around with plenty of “steel” (in the form of billions of technocytes and technosomes, etc.) scattered all through their “flesh”, they would say that, now wouldn’t they?