This is a crop of a photo that was enlarged by 400% using the Nearest Neighbor resizing method. This makes the effect of the different sharpening tool better visible. The test photo looks quite soft, but you can already see that it contains some noise. The softness keeps the noise down, but it can be expected that the noise will become more visible by sharpening.

Test it yourself!

Don't grab the image above, because it was upsized to 400% with Nearest Neighbor interpolation, so it is useless for sharpening tests. Please get the image in lossless PNG fomat here: ArmOriginal.png

Open this image and set the sharpening tool to 300% intensity and a radius of 1.0 pixel. If the tool doesn't have an intensity or radius setting try to produce a setting that is similar sharp as the examples below. Then set the zoom to 400% and compare with the examples below.

FocalBlade 2 ($70 / $40):
FocalBlade 2 doesn't amplify color noise, in fact it was even reduced here with the new color noise reduction feature. FocalBlade 2 also keeps the noise on the blue skirt low while still giving it a sharp look. The JPG blocks are as good as invisible. There are no ugly white halos visible because of halo reduction. All in all, it manages to produce a high sharpness without producing side-effects.

Old FocalBlade 1:
FocalBlade 1 did not have an option to remove color noise, so it is still there, but not amplified by the sharpening. The surface areas, e.g. the blue skirt, look softer, because FocalBlade 1 used less punchy defaults for the edge mask than FocalBlade 2. You still see white halos here in the dots and the border of the white blouse. FocalBlade 2 by default uses halo reduction which does not produce extreme highlights. Nevertheless you can still achieve this look in FocalBlade 2 with the "Version 1 Defaults" setting if you wish.

$100+ Tool:
This tools offers multiple-pass sharpening and only presets and no preview. It takes quite some time to find the best sharpening, because the presets are only optimized for general scenarious, so it is very difficult to adapt the sharpening to certain images.
If you choose settings that produce a lighter sharpening, it can do a more or less nice job. If you want to do stronger sharpening you often get an overprocessed look with a lot of artifacts, even if no extreme white halos appear. Another bad side-effect is the reduction of contrast and saturation in the image.

$100+ Tool:
No manual sharpening possible, only adjusting the auto sharpening. You also can't deactivate the automatic color, contrast and brightness correction. There's only one slider for sharpening and one for noise reduction.
The tool manages to smooth the arm, but not the color artifacts at the borders of the arm. In fact they get even more visible. Additionally the image didn't get really sharp although the highest setting was used.

$70+ Tool:
When tweaking some settings of this tools, you can avoid that the color noise is increased. The other noise is still increased which can't be effectively avoided with this tool. There is also no Radius option available.

$50+ Tool:
It doesn't amplify the color noise on the arm, but it produces a very ugly pattern on the arm. The edges in the photo are enlarged and unnecessarily emphasized.
After applying this tool to the whole photo, it looks quite dirty, degraded and not really sharp.

$50+ Tool:
This tools only offers a few presets and nothing more, so you can't fine tune the sharpening at all. It keeps color noise constant, but increases other noise types. It also adds a bit of salt & peper noise.

$50+ Tool:
The color noise on the arm was slightly amplified. A lot of hard edges were produced, because the gradient around the edges was removed. Although the surface of the blue fabric was smoothed, this tool still left several highlighted pixels which stand out.
When applying this tool to the whole image the result was much worse, because it produced chopped edges with strongly amplified color noise.

$30+ Tool:
This tool doesn't allow really strong sharpening, only up to 100%. Additionally some of its features easily produce hard edges.
It flattens the surface areas too much and intensifies the edge areas so much that they look quite aliased.

$20+ Tool:
Although it manages to keep the color-neutal noise down, it amplifies the color noise very much. It doesn't sharpen some areas very much, so many images will still look too unsharp with it.

$20+ Tool:
One setting of this tool only sharpens the edges (see image) and one produces a result that is even worse than Photoshop's USM filter. The edge sharpen result is quite bad. It left the surface areas untouched and blurry. Whereas it didn't sharpen all edges, it sharpened some edges too much. All in all, the result still looks quite blurred.

$20+ Tool:
This tool keeps the color noise constant, but it removes the gradiations along the black lines and makes them stand out to much. It smoothed the skin area a bit, but several individual pixels stand out too much.

Freeware
Tool:
The sharpening is a bit weak and the noise is only slightly amplified. However, the color noise at the arm has been spread to a larger area and a blocky pattern runs through the artifact areas. A similar blocky pattern becomes visible on the blue fabric.
It works better than some of the other tools, but as it modifies essential image data, it should only be used with great care and at low settings.

Freeware
Tool:
This tool offers no Radius slider. The sharpening effect is in the same league as Photoshop and PSP.

Freeware
Tool:
This tool only offers an Amount slider. The 50% setting was used for this example. It causes the same problems as the other USM plugins in this round.