I'm sure one of the makers will give a better answer, but I've read that the pleats on a hand-stitched will hang better because the kiltmaker has greater control to adjust the line of the stitch. From my experience with other garments, I'd say machine stitching will usually look straighter and neater then hand stitching, but hand stitching will hold better and last longer. If that's true, and a hand-stitched kilt will last for many years longer, I'd say it's well worth it. You're plunking down a solid investment for a machine stitched kilt anyways.

But, 'eck, if machine stitching lasts longer and looks better, I'd be happy to save the extra money.