There was a good exchange of this same topic somewhere over on the Bullet. But for steel, at that power lever/CID and well above, the Ultra was pretty highly regarded. RMRE uses Manley in there builds which exceed your limits. If you are on the margin of using a 'cheap' crank you may want to consider aluminum however. The comparison post only gave you a reference of cross-sections. The entire process of manufacturing gives one strength over another which goes beyond mere cross-section and weight comparisons. Processes that minimize inclusions etc.