Is grass-fed beef more nutritious?

Like us, cattle have a very different metabolic response to eating lots of green vegetables (grass in this case) versus grains. This paper recently published in the Nutrition Journal reviews research performed over the last thirty years:

"Research spanning three decades suggests that grass-based diets can significantly improve the fatty acid (FA) composition and antioxidant content of beef, albeit with variable impacts on overall palatability."

Personally, I much prefer the taste of grass-fed beef as do others I know. They detail some of the differences:

"Grass-based diets have been shown to enhance total conjugated linoleic acid isomers...and omega-3 FAs (fatty acids)on a g/g fat basis...grass-finished beef tends toward a higher proportion of cholesterol neutral stearic FA and less cholesterol-elevating SFAs such as myristic and palmitic FAs. Several studies suggest that grass-based diets elevate precursors for Vitamin A and E, as well as cancer fighting antioxidants such as glutathione and superoxide dismutase activity as compared to grain-fed contemporaries..."

They alert consumers to the different color grass-fed beef may have due to a higher carotenoid (vitamin A precursor) content as well as different cooking characteristics.  They don't, however, note in their paper how much more humane a grass-fed lifestyle is compared to grain-fed factory farming. By the way, how do you think studies on an association between red meat and various cancers might have turned out if only organic grass-fed beef was used...?