CSS gradients vs background Image?

CSS gradients vs background Image?

Some years ago, I've seen a lot of CSS codes using background-image:
url(xxx.png) simulating a gradient background filter, since only (please,
correct if I'm wrong here) IE proprietary filter would provide CSS
gradient.
Nowadays - keeping in mind the most used browsers today and portable
devices browsers (smartphones/tablets), should I use:
CSS gradients, with 1 background property for each engine
OR
background-image: url(xxx.png), 1 tiny image (but still a browser request);
?
And how about IE9 issue there I have seen in some CSS gradient generators?