tron said:
The only use where I would think of 24mm 1.4L II would be astrophotography.
Yep, I had the same thought. AF would be a non-issue for me for landscape and architectural work, as I'd be manual focusing most of the time anyway.
The 24 T/S is going to be better in every regard than the 24L, except in AF and low-light. So, if you'll use the 24L to shoot people or other scenese where you need AF a decent amount of the time, then you'd have to get that. Otherwise, I think the T/S opens up more possibilities.
This review has comparisons of all the lenses in that range (both 24mm T/S, the 24L, 16-35, etc). If you compare them at f/3.5, the TS is noticeably sharper and has much less CA. That's wide open v a lens stopped down 3 stops. The same is generally true at f/4-f/11...it's just sharper across the frame because of the nature of how it works. And of course, there's the ability to do pano's, etc
http://the-digital-picture.com/Reviews/Canon-TS-E-24mm-f-3.5-L-II-Tilt-Shift-Lens-Review.aspx