If you’re looking to purchase an e-reader and just can’t fathom the minefield of differences, PaidContent has compiled a comprehensive and very useful chart that compares the Amazon’s Kindle 2 and Kindle DX, Sony’s Daily Edition, Barnes & Noble’s Nook, Plastic Logic’s Que proReader, and Apple’s iPad. The chart compares the six most popular e-readers in 20 categories including hardware spec, software and content.