My ratings appear to be biased towards the 3.5/4 mark; however, that's not because I view that as an average album - it's because I'm more likely to check out an album that I'm likely to enjoy, more likely to rate an album that I listen to (which is often because I like it), and more likely to skip through the rest of an album if I don't enjoy the first couple of tracks, in which case I don't feel like I know the album well enough to rate it.