The steam mechs of the core are a little more mech and a little less magic. Such mechs are well taken care of by their handlers, although ages of warfare makes most steam mechs look less shiny. There is a darkness to how steam mechs are viewed in the core worlds. The constructs are seen as dangerous, dirty, and frightening even though they are required for the security of the Empire of Monarchs.
Steam mechs in the far reaches of the Aether (like those seen in Rielunspace) wouldn’t be as advanced as those near the core worlds. Such mechs are more magical than mechanic, and they are built for their aesthetics, especially by the Elven Flotillas. (imagine a Elven Warbird spelljammer morphed into a mech and you envision what I see in my own mind.) The steam mechs of Rielunspace are considered primitive by core world mecha designers but the effectiveness of the magics they wield cannot be understated.