A guildie suggested that I install Pawn. This addon can be configured to show you a score on your gear based on the various stats that you want to judge on.
As a Destruction warlock, I am highly interested in pieces with high amounts of hit, spell power, haste then crit. To simplify gear selection, I've set up scales. These scales weight each stat, generating a score.
My favorite scales:
Yesterday, I found a new way to look at scores. When you see a new item, for example it's linked to you, right-click that display. Pawn will popup a new display that compares line-by-line your equiped item to the new item. Wow! No longer need to open my character screen and look at the item score to compare!