I used a HUD many years ago. I hope they have improved.
You get plenty of info on all of your opponents, so you will never have to worry about not being able to read them. Nice that the HUD can keep track of all your online opponents and bring up stats instantly. Wish my old memory was able to remember even the simplest things.
From what I recall of the HUD I used, I found it valuable to know how often my opponents entered the pot, from what position, and how often they raised pre-flop. It also tracked their winnings, so you can avoid the players with monster bankrolls. It would appear that they know what they are doing.
Good luck.