HRD Gear in my AW mags is hot butter in Curtis Vector. I also picked up Accurate Mags and primal rights kits to try, but haven't used yet. Main goal there is mag extension for 12 round stages. Heard MDT 12 round metal mag was good, but some say older springs ran better, thinner than the newer ones apparently. MDT will send you older, thinner springs. Got a pair inbound myself for another rifle. No inserts available (yet) for MDT, but rumor is one in the works.
Dan