Isis arms are made with mild steel and have shitty welds. SPL are Chromoly and are tig'd they're nothing at all alike and all the chinese shit run metric rod ends which most of the time you cant get decent replacements for.

So that's a terrible argument, and unless you have access to a decent tubing supplier, rod end supplier, machinest, and are decent at Tig welding you cant make anything half as nice.