I originally bought this book used and later discovered that this was the ideal situation. It is handy to have all of Shakespeare's works (plays and sonnets) under one cover, but there are several drawbacks. Each page is split into two columns, causing the plays to be read like a newspaper. Since linebreaks are important in Shakespeare (remember the iambic pentameter), some lines are too long for the margins, causing the remaining words to hover like ghosts away from the sentence.
Also, this book contains no footnotes. This is mainly how buying the individual play is superior to the collected works. Olde English isn't always intuitive, and this particular book leaves you to find out a word's meaning for yourself.
But this book certainly looks pretty on your shelf. :)