Hi Josh,
I have held and seen Vietnamese weapons of both very high and very poor quality, some items of the same type but at each end of the scale....I guess like everything, budget plays a part and does usage and region of manufacture.
Last year I viewed a collection of 7 yanyuedao from the region and was impressed with several highly details, fullered and well finished blades but others were capable but poorly finished.
After seeing these I feel the one presented in this link is also from the Vietnamese regions;
http://www.vikingsword.com/vb/showthread.php?t=13064
I am sure the crude look accounts for a particular use but what the exact reasoning behind it is unknown to me but it does look very capable.
Gavin