These outputs aren't fully stripped, just debug-stripped I've noticed as well. That doesn't make that big a size difference for MIPS though. A proper strip does reduce mingw size by about half from 600kb to 300kb. Still, outputs are in the 500kb+ range for most platforms. And this isn't really an issue for most, but for MIPS I'm looking at embedded use with devices that only have 4-8MB flash storage, a 2.5MB hello world binary isn't useful there.