We found it to be pretty close to what we determine by eye, except when using 5 and 10 MP cameras, in which case it overestimates resolution by far (listing 2036 when the chart only goes to 2000and it draws the red line seen in the image at 1600). It has worked accurately for 720p, 1.3MP, and 1080p cameras, however.
This short internal video gives a glimpse of what we saw:
What worries us most is that this is freeware, with only a short manual and little to no support if we have questions or issues.
We are also considering using Imatest, which is far more complex, but measures numerous parameters. Imatest has told me that some manufacturers in the surveillance industry are using it. It will test resolution, dynamic range, sharpness, color fidelity, and more and more. Full list here. This video shows just one portion of it:
Does anyone have any experience with either of these packages?