Mozart's work I feel was much more polished and crisp than Vivaldi's, I guess I would have to compare it to one of Mozart's concertos like, Piano Concerto No. 21. Both are concertos but I feel like Mozart's pieces are much more dynamic and alive. Vivaldi's music sounds like music, but with Mozart sometimes you forget your listening because its such an organic composition. I listen to Mozart and become lost in the thought and essence of the music, when I listen to Vivaldi I just feel fancy.