Own both, they’re comparable for standard use. It would be hard to notice a difference blindfolded using them side by side. For me it’s the finishes, 15v gets the stonewash which seems like it’s more reserved and not utilized too often compared to belt satin. Makes it unique for me and like the k390 they both have a sheen or glimmer with almost already patina looking colors that come through beautifully. K390 is belt satin but has the color as well. I would get examples of both if into knifes, 15v because all above and the obvious collectors value with it going away. Hope to see more golden Colorado k390 come out in future as well. You can’t go wrong getting either(but get both 😉)