Canon wide angle lens question (upgraded from a 40d to a 5DMark3)

Now that I've upgraded from a 40D to a 5dmark3, I need to update my wide angle lens. I've been using a 10-22.

I'm mainly looking at the 17-40f4 and the 16-35 f2.8.

Will mostly be used for landscape, sunsets, night photography (slow shutter speed on a tripod). Some people stuff here and there, using a flash.

I know that the 16-35 is a superior lens, goes to 2.8 and works better in low light without a flash, etc etc, and I've read all the reviews, but there is a pretty big cost difference and I could apply the savings elsewhere.

My main question (and I don't see this in any reviews) is has anyone switched from a crop sensor & 10-22 setup to a full frame and 17-40 setup? How do they compare? Seems like the 10-22 multiplied by the 1.6 crop would provide a similar field of view as a full framed 17-40? How does the sharpness compare, mainly at the wide end? I've seen some complaints about the 17-40 not being sharp at the edges, but I've also heard that about the 10-22, and that lens is fine for me.