Keep 35 1.4L for portraits with background or is 24 1.4L II same IQ?

I would never sell my 35 1.4L, but now that i'm looking for something wider for urbex (dark abandonned places), I doubt if I should replace it with 24 1.4L II or not.
35L is one of Canon's "holy trinity", but is the 24 1.4L II likewise good or is it a class lower?

35L is nice for portraits with background, i'm a bit afraid that 24L II would be too wide on fullframe for portraits with background or that the IQ wouldn't match the 35L.
People say that 35L isn't suited for portraits as it would distort the face, but I don't see why as you mostly take the picture further of the subject to get more background, not close to distort the face.

Iv just bought the 24mm, and I also own the 35mm.

I can't offer any advice for portraits, but I would say that my 24mm is slightly sharper than my 35mm.

I have both, and optically the 24L II is better than the 35L. Less CA, and a hair sharper. Don't listen to the people that say not to use the 35L for portraits, It works great for full body shots, but there is some distortion if you fill the frame with their head. Nothing beats the 24L for environmental portraits though, the field of view is significantly wider. The 24L II is a lens that has grown on me, shooting wide takes work.

Why do you keep 35L if you have the 24L II ?

2.8L wrote in post #14737325
I have both, and optically the 24L II is better than the 35L. Less CA, and a hair sharper. Don't listen to the people that say not to use the 35L for portraits, It works great for full body shots, but there is some distortion if you fill the frame with their head. Nothing beats the 24L for environmental portraits though, the field of view is significantly wider. The 24L II is a lens that has grown on me, shooting wide takes work.

CanonYouCan wrote in post #14740289
Why do you keep 35L if you have the 24L II ?

They are different lenses...really. The 35L is closer to the 50L than the 24L to the 35L in term of perspective. An extra 11mm on wide end is really huge.

I have both and use both for different purposes.

^ ^ This.

Try out your 17-40 at 24, then at 35 - it's a huge difference. As sonnyc observes, different lenses, different uses