The two are basically the same speaker but..... Vista vs Vantage: Vista woofer box is slightly larger and un-powered, crossover points slightly different along with different sensitivity. Personally I liked the Vantage over the Vista by themselves.
Mate the Vista with a Depth Sub and you have basically the same cost, but with "probably" better low end (subjective opinion). I am just thinking out loud here from listening to both, but never hearing the Vista with a Depth.