Salvo Elixir is 90-95% in reference to the scent profile, but performance and depth is where these two are separated.
Salvo performs on a moderate level. With the price point diffence, it is not a bad choice for a short term Savauge substitute.
Sauvage Elixir is both a masterpiece and a beast. The longevity is phenomenal (definitely does not to be reapplied within a 12-16 hour period), but the sillage has caused people to walk around a store more than once to ask what I am wearing. I had one person follow me out into a parking lot just to tell me that it was the best cologne that she had ever smelled.
So in closing, Salvo is a toned down version that would be perfect for those that do not want to draw to much outward attention, but enjoys the scent profile. For me, well, I like to make a statement when I spray.