In 2011 Boris released 3 albums! And yes, Heavy Rocks is the most heavy of them. The other two are quite poppy, the metal/drone/noise freakouts of the old Boris seems to be gone. The standout track on Heavy Rocks is the doomy ballad Aileron, you can listen to it below. You can also read reviews from AllMusic and Metal Review.
[Go to the post to view the Bandcamp player]
Their new remix album, cheekily titled New Album is available here.