Wow, your configuration is a lot like mine and you say microsoft composite editor is quite quick to stitch 21 16mpx images “panorama” I’m rather impressed !
Being exclusively on GNU/Linux since … windows 2000 (never installed XP) I tend to lose comparison with M$ bundled software but having a baseline bench would be interesting !
Even more given that Xpano is already a lot faster than hugin even at the stitching calculation itself…