yeah, you can combine it with any other shaders and PP effects such as shadow mapping.
This implementation has virtually NO black or light halos at all. you can use any blur you want, as many times as you want.

As for scaling, the best results show on full resolution, however, by rendering a smaller view, you can increase the framerate. The shader runs on my computer at 30 fps (1440x900 resolution (full) on a single GeForce 8700M GT graphics card). This also includes high resolution shadow mapping and a scene of almost 1 million polys. This is resonably faster than the original SSAO from Crytek and uses integrals to accumalate the occlusion over a fixed porjection circle rather than sphere.

In addition (as you can see from the images), the ambient term is calculated with as little offset error as possible. This means that even though the occlusion does not "bleed" (has "halos"), it IS safe to further blur the results.

-mike-