I'm wearing Armin at a con in late may and eventually re-using the scouting legion uniform for Hanji.
I've just finished putting together the leg portion of the harness, the thing is really confusing to put on but simple enough how to figure out how to make. It's the sewing together the strips of vinyl and buckles that's the worst part. The boots have been the most annoying part so far though, I don't think I've ever modified shoes that much before.
I'm making the manga version of the 3DMG, the anime version, especially with the reduced number of blades, doesn't do it for me