To replace my 17-40, or not to replace my 17-40

In need of a little advice here.

The 17-40 f/4 I'm using is due for replacement. I'm wondering if I should get the same lens or if there are better options worth the difference in price.
I specifically shoot real estate and I am pretty happy with my setup. 95% of my work is done @ 17mm, f/11, MF, on a FF body sitting on a tripod. Ideally, the 17mm t-se is my main wish but I'm not sure the benefit to cost is worth it for me.

I'm not brand loyal and I don't even care if I need an adapter, nikon or old russian lens, as I shoot in MF. My main priorities are distortion, flare resistance, sharpness at f/11, and color.

What are some other options that make sense for me that are not the 17-40?

Thank you!

16-35 f/4 has IS. If that's not as important I would stick with the same lens.

Sigma 12-24?

The 16-35mm F 4.0 has obsoleted the 17-40mm lens. Go for it and be happy

Not for me. While IS would be nice, and this is Canon's least expensive IS implementation in an L, I need 35-40mm a lot more than I need 16mm. I wouldn't switch if they were the same price. Right now the 16-35IS is $360 more than the 17-40. That stuff matters to some of us.

The latest 70-200s have not 'obsoleted' the non-IS versions. Different strokes, and all that....