Thanks for your feedbacks gent's.
Prior writing this topic, the only thing that make me think twice is non AF. This could be a huge issue for me. My current 16-35 II is fine when shooting at smaller apertures f11 or smaller. However, there are times I need to shoot indoor f4 to 5.6, the IQ is quite not same.
Another Q: is there any tilt-shift with AF?
Thanks surapon for sample photos. Those tall buildings look great with tilt-shift.
Not that I'm aware of. I think part of it is it's a specialized lens, and it's specialty will very much tend to be used on a tripod and longer exposures as necessary, so AF wasn't a thought. Might actually be real engineering issues since the entire barrel needs to shift & tilt, and even rotate. If they did, it'd probably add a good bit to the cost I'd imagine, and it's already expensive enough as is.
Is the issue that you need to shoot UWA indoors, but not on a tripod where you could do a longish exposure (e.g. moving subject(s))? I guess you gotta stick with the 16-35 v2, and step back a bit so that you can crop in somewhat to remove the corners. Or just live with what you have. Honestly, I don't think you generally can shoot at f/11 indoors, unless you have a ton of light coming in, which might be common for where you shoot (certainly not where I shoot!).