finally, some decent samples

Okay, the second set of properly-focussed, properly-exposed samples (the first was in the PhotoZone review). Finally, we can see what the lens is truly capable of.

http://www.pbase.com/malcolmp/1755_f28_is_samples

Comments

The evidence is mounting that the bokeh of this lens is just plain poor. Out-of-focus backgrounds look smeared and muddy, likely, due to the strong astigmatism of the lens. Out-of-focus areas in bright, high-contrast shots are ugly. Out-of-focus highlights at f/2.8 show both a bright ring at the edges, which is much brighter in the direction of the light source, as well as inner bright rings that make it resemble a target. All in all, quite distracting when viewing at 100%, but much less so at reduced sizes (i.e., typical print sizes).

That means this is not the "leave your worries behind" lens I was hoping for. It seems capable of producing stunning pictures, but care must be taken to manage background blur.

I was further hoping that this lens would reduce the amount of post-processing necessary. The poster's comments about having not as good color as the EF 17-40mm f/4L - more or less backed up by the sample shots I've seen so far - appears to deflate this hope. But even my primes benefit from extensive post-processing, so this probably wasn't a realistic expectation in the first place.

That's the bad news. The good news is that the stuff that is properly exposed and in focus is ultra-sharp. These samples are pretty much proof of PhotoZone's findings. Also, contrast seems to be good enough for me. There was one comparison between this lens and an EF 20-35mm f/2.8L already posted, but it was so sloppily executed it was useless, and I didn't post it here.

Conclusion

If you learn how to use it, and put the time in to post-process, this lens is as good as the Canon primes in its focal length range. Of course, that's just based on second-hand information; we'll see how it goes when I actually get the lens.