I am not a MM and do not have level 3 and I agree with what you said BUT I think level 2 is a good indicator of pressure in either direction and in many cases you can see a share price increase and a wall of shares will go up at ask and suddenly the increase stops and often changes direction. I believe you can get a level 3 access through some trading desks if you have enough $$ but it’s like leasing a terminal, it’s not yours.

You can get a good idea of what’s going on by level 2 though.