From the 2+2 Forums: "What % of players use a HUD?"
A beginner asks about head-up displays in online poker. I liked this response:
Using and understanding how to leverage the use of your HUD is the main reason of success for the vast majority of poker players. It speeds up you learning so fast it often pays for itself in days. The fact that it is so cheap is just amazing.
I think I would be a winning player without a HUD but the day I got my first poker software (called Poker Copilot for Mac) I instantly found and fixed a bunch of leaks in my game.
You can not underestimate how valuable it is, it is better than any book or poker video for the same price.
I couldn’t have stated it better myself.