These kinds of comparative testing results will vary depending on a variety of factors to include but not limited to who conducted the testing, what they were testing for (type of threats, attack vectors, exploits), what versions of anti-virus software was tested, what type of scanning engine was used, and the ability to clean or repair. There are no universally predefined set of standards or criteria for testing which means each test will yield different results. As such, you need to look for detailed information about how the tests were conducted, the procedures used, objectivity and data results. Read Anti-Malware Testing Standards Organization: AMTSO Fundamental Principles of Testing.
Each security vendor uses their own testing/analysis methodology to identify various types of malware so the detection results are not always the same.
Some of the testing criteria and standards may even be misleading.
...for some unknown reason...the renowned German test lab AV-TEST has quietly (there was no warning) modified its certification process. The changes mean that the certificates produced by the new rules are, to put it mildly, pretty useless for evaluating the merits of different AV products...With AV-TEST’s new certification standards, the onus is on the user to carefully investigate the actual results of each individual test…they may find that a product that blocked 99.9% of attacks has the same “certification” as a product that only blocked 55%.
Comparative testing: A bit of background for the uninitiated
Further, if you're dealing with zero-day malware it's unlikely the anti-virus testing is going to detect anything. It takes time for new malware to be reported, samples collected, analyzed, and tested by anti-virus/anti-malware researchers before they can add a new threat to database definitions.
As for Tweaking.com-Windows Repair...it is fine to use as long as you stay away from any optimization features.
There are numerous programs which purport to improve system performance, make repairs and tune up a computer. Many of them include such features as a registry cleaner, registry optimizer, disk optimizer, etc. Some of these programs even incorporate optimization and registry cleaning features alongside anti-malware capabilities. These registry cleaners and optimizers claim to speed up your computer by finding and removing orphaned and corrupt registry entries that are responsible for slowing down system performance. There is no statistical evidence to back such claims.
Bleeping Computer DOES NOT recommend the use of registry cleaners/optimizers for several reasons.
Why you should not use Registry Cleaners and Optimization Tools
Be sure to read Microsoft's support policy for the use of registry cleaning utilities in that topic...Microsoft does not support the use of registry cleaners.