I took some time out this afternoon to examine the image you offered and make some tests, which I actually printed, taking on board Jeff's advice that one does need to look at the printed outcome when it comes to sharpening.
I notice that the version you posted is at a resolution of 100ppi. That really is below the comfort level for such testing, but it works. The more usual situation would be higher resolution images, so what I came up with may be of limited general validity, but nonetheless here goes.
The first thing I did was a careful examination for noise. I do this with Noiseware Professional. I converted a copy ofthe image to Lab to insure I was getting a clear analytical separation between luminance and colour noise. At all four frequencies it measures, Noiseware found insignificant amounts of colour noise. Only at High frequency was there more than 10% noise and this is confined to the very darkest areas of the image (luminance below level 25, such as the sides of the roof dormers). At most levels the amount of luminance noise ranges from less than 10% to insignificant. The facades of the buildings, the road and the roofs have either insignificant or very low levels of noise - nothing that would bother in a print. So I decided that noise is a non-issue for this image.
Moving on from noise, I turned to PKS and found the optimal settings to be for Capture Sharpen - Hi-Res Digital Superfine Edge Sharpen with opacity of the master layer reduced to 70%, and for Output Sharpen, using Epson Enhanced Matte paper and dimensioning the image (without resampling) to 6*9 inches for printing on a letter-size sheet it comes to 133ppi, therefore the only feasible setting is Matte 180ppi. I reduced the opacity of the master layer for this set to 50%.
Between capture sharpen and output sharpen, I made a Curve Adjustment Layer with level 255 remapped to level 230and input level 24 remapped Output 25. This brightened, increased contrast and re-darkened a bit. Gives the scene more snap with no clipping.
Then I made two versions of this structure: one using John Paul Caponigro's High Pass mid-tone contrast enhancement technique (available on his website) with default opacity of 20% and one without it. This is done with a Stamp Layer and done before Output Sharpening. Comparing these two prints, I preferred the one without the mid-tone contrast enhancement. Combined with Output Sharpening, it's a bit too brittle for my taste.
Then I turned to Focus Magic. I have an evaluation copy of this program, so I had to convert your image to JPEG. That may introduce an impurity in the comparison, so I need to mention this here.
Anyhow, I made the same Curve adjustment layer first in hi-bit mode, did NOT do the local contrast enhancement, flattened, converted to 8-bit, converted to JPEG at highest available quality and Saved-As.
Then I opened this image in FM, and selected the "Focus" filter because for this image none of the others seemed to apply. I thought the resolultion filter would do as well, but it seemed quite ineffective - perhaps because this is an evaluation copy the advertised preview of the effect doesn't show. Since this image has no motion blur, Focus seemed the next most obvious option, based on what is described in their Help manual.
So I made two images with that - one at level 2 and the other at level 4. I printed those as well. The image at level 4 is a toss-away - very obvious halos. The image at level 2 is acceptable. When I put this image side-by-side with the PKS image excluding the mid-tone contrast enhancement, I find the PKS result generally preferable. It is "sharper" (but perhaps had I run FM at level 3 it would have been awash!), the detail of texture in the road and the roofs is better - and this is not sharpening noise, I'm talking about real edges. But more a propos, the FM result seemed uneven - it did a pretty good job on the left hand-side of the image, and as one moves to the right, the quality falls off relative to the PKS image - such that the blue and white sign for the M&S shop is very obviously more distinct in the PKS result than in the FM result.
That's as far as I've taken it.