Boxer primed is the standard for American ammo, and Berdan is mainly European. Boxer is easily reloaded because of a single flash hole and the Berdan can be reloaded but is a more difficult proceedure (primers can't be punched out with the Berdan's two flash holes). Berdan prirmers are difficult to find in the US (even harder than Boxer primers are now). But some fellers have gone to all the work of reloading Berdan primed brass and some have converted Berdan style brass to Boxer style (google berdan to boxer conversion). Some have modified Boxer primers to work in Berdan brass, but again it's a lot of work.
Steel cases can be reloaded. Several folks have reported 12 to 13 reloadings with steel cased .223/5.56. No it won't wear out your dies much faster than brass, but it is a bit harder sizing. Steel usually doesn't last as many reloadings because it becomes work hardened and brittle, splitting sooner than brass, especially handgun cases. If cleaned in a tumbler the protective coating may be removed and the bare steel can rust. Most don't reload steel because brass is still available (mebbe harder to find now, but still around) and much better suited for modern ammo/reloading.
Last edited by mikld; February 16th, 2013 at 12:33 PM.