Forgive me to add:
Suppose you are taking notes on a player using HUD. And it is possible that, that player is also taking notes on you. You know about his trend and he knows about you. In these conditions can you make any profit from that player? Or that player can make any profit from you? I think tools may be helpful or of advantage for you if other player is not taking notes on you.
A player using HUD doesn't have notes on me, he only has my stats like how often do I see flops, how often do I re-raise pre-flop, how often do I fold to opponents aggression etc.
That doesn't say nothing about the exact
hands I am doing all the things above with. So if QJs is in my re-raise range, HUD doesn't show that, but I one could note something like that if the hand got to showdown!
That being said, YES, you can definitely have an advantage over someone who is noted, regardless of him having notes on you, or using HUD.
Recently one of the major poker room abolished the use of tools. why? The reasons i can think of are:
One, use of tools by all players makes the game more mechanical. Less use of brain and judgement makes the things a routine job. How a player can show his skill?
Second, more use of tools means more information about the players. This could lead to manufacture of more BOTs like software which are already threatening the online poker industry. After all nobody wish to play with bots. It is difficult to beat them.
The real reason IMO that poker rooms are forbidding HUDs is that they are not fair.
Let's say I am recreational player who is not playing often so don't have need for HUD, or I just don't have enough money to buy it. I am then at a disadvantage when facing opponents who are using such softwares.
Now if that is something I'm aware of, I could decide not to play online, or at least not to play online in that particular room that allows the usage of softwares.
The room then loses money, because it loses players. At the same time, no HUD is paying anything to the rooms, so poker rooms don't have any gain by allowing players to use them, but could potentially have losses.
Another reason is possible exploitation!
online poker rooms eventually develop their own HUDs, and for a price, you can purchase those, directly from developers - poker rooms (PS,
888, ACR, PP etc.). Whoever uses software would 100% rather purchase it from the rooms, knowing there would be no bugs, issues or other bad stuff...