Ok, I set FOV to 80, reduced my screen resolution to 1920*1080 and got rid of the black bars in the ENB. Same effect, getting my ~34fps with
the unedited ENB and DOF off.
Edit:
I have tested many ENBs now. The Grim and Somber ENB looks really great. Unfortunately it is unplayable for me. Everything
seems to be slightly blurry with CoT installed, no matter what settings I change. I managed to get a big improvement with the "blur" problem but it still
feels like you are looking at a 2D poster, rather than a 3D game. I have to admit that the Grim and Somber ENB made me feel a little bit sick : /
It's probably due to the combination with CoT.
The Phinix Natural ENB is one I really like, however it left me a little bit disappointed. It feels like too little of the Vanilla-CoT feeling gets changed, were
do all the FPS go? Of course it becomes obvious as soon as you pay close attention... still, a little bit too.. normal? for me.
I went back to the Unreal Cinema ENB and it eventually had me convinced. It is slightly too bright/white for me during day time but overall
it is doing a very good job indeed.
Especially the water looks the best out of all ENBs I tested. Phinix Natural and Grim and Somber turn it into an unfortunate swamp.