There is definitely a difference in luminosity and range of color. To me the greatest advantage of oils, however, is its depth of dark intense glazings like with Ultramarine or Alizarin crimson. No way to get such a dark deep blue with acrylics! But since I rarely need this saturation I don't use it. Another advantage is the way how you can carefully add and remove glazings. With acrylics you have to be very careful with this because once it dries it can't be removed.