So what you're saying is, on the PC I have to find a way to press the jump or crouch buttion at the same time as I do a direction key, plus the combat mode button while I'm moving my mouse to be able to see the corsshairs on something two stories taller then me, and then fire at a very specific moment.
That is a tall order for me. For one I am left handed, so I use the numeric keypad for controlling Lara. In that layout in every other game I can use the derection keys next to the numeric keypad with my thumb for crouch, etc. With this game I cannot because they are hard coded to menu navigation. This means I have to cram them all on the mouse and numeric keypad, making quick manuvers like this nearly impossible.
I understand how to do an adrenaline dodge. I have read several tutorials and watched a few youtube's, so I know when and how it "should" be done. However, like others it is just not doing it. I have tried for hours and gotten nothing. T-Rex is usually right on my tail so I have no room to see xhairs when he charges, and I rarely have time to figure out if the spikes are still behind me. The few times I do get things lined up perfectly, she simply will no perform the manuver. This really needs to be patched.