I once had a great uncle named Vance that I have heard many stories about so it is embedded in my subconscious. I think I prefer Lance overall but because of my uncle's time in WWII and the stories of him I imagine bravery and resourcefulness and the ability to think on one's feet. But even without these stories I would still imagine it a name of that particular generation and the impression that implies, that of an era of men that gave everything for their country and families. I do not hear this name very often at all but when I do it makes me happy. It's a good, solid name and I think any boy should stand tall to have it. If you are considering using it I say go for it, it's a nice choice.
I actually kind of like this name. Sure, it's different, but I think it sounds strong, although it should probably be used as a middle name (for a guy, of course).
When I imagine someone with the name Vance, I think of a guy with slicked back hair and a thin mustache who says things like "That's right my dear. Now run off. We men have important things to talk about."