If I'm in an area with an abundance of vegetation or brush, I don't spend much time on brown (decomposing)... i'm looking for green or grey. If it's isolated brown brush, definitely give it a try, but my money is on aged brush and fresh brush.
One thing I'll add to this thread: the more cover/structure a body of water has, the less significant each piece becomes. A lone brush pile almost assuredly has fish in it, but when there are 100 brush piles, they won't all hold fish. When you are fishing "cover o' plenty", look for things that stick out. Abnormalities. Also, go back to the basics: focus on cover that is by key structure like points, humps, channels, deep water, etc.