When talking about Inkjet [or UV Flatbed] direct to metal. Both will work.
With UV Vutek, the ink will sit on top of and cover the shine of reflective surfaces. Defeating the point.
That's what UV-curable laminates are for. You can make them as glossy as you like.
But MOST importantly the Gamut of Sublimation trumps them all. And that is what I believe to be the Big Wow Factor of Sublimation printing.
Actually, the gamut of aqueous inkjet significantly exceeds that of dye-sub transfer to metal. If you don't believe me, print an image containing lots of red, green or blue on inkjet and on dye-sub, then compare them.
Dye-sub metal's big advantage is the Cibachrome-like smooth surface and ultra-high gloss, which allows for very deep blacks. But inkjet can print a greater gamut and, so long as you have a smooth surface to print on and a high-gloss laminate, can create an image with just as much impact.