I believe reading outside of my genre for specific elements and writing devices is also useful. For example: I have certain action scenes that require imagery involving guns and the mechanics of shooting guns. So, I picked up a couple Tom Clancy novels to see how he approaches these elements. I am not writing about covert operatives on top secret missions, but I can apply some of their expertise to my characters in my crime novel.
I plan on reading a few popular western novels to help me characterize a present day sheriff in my story. I don't have a romantic element (yet) but, if one arises, I will surely pick up at least one good romance novel for reference.
I hope that by reading and learning from experts in their specific genre's, I will be able to strengthen all the various elements in my story. As for the advice about reading to improve writing, I think this is very solid advice for developing your writing style and voice.
Read, read, and read some more. Write, write, and write better.