VoodooShield REALLY should not slow your computer down, especially the latest version...
VS 5.97a beta
https://voodooshield.com/Download/InstallVoodooShield597abeta.exe
SHA-256: 4d7622bf1e7f62b6214a82d9fe27350ce9d2a55f8a0f5d89d25830d5937f23b6
If you do continue to experience a slowdown, we need to look at the CPU, RAM and HDD usage, since those are the 3 components that are suspect during a computer slowdown. We actually have a utility called Bottleneck that will help you determine what might be the cause, you can download it here...
https://voodooshield.com/Download/InstallBottleNeck.exe
As with some other security products, there are somewhat similar products in the deny-by-default space, but there are no direct replacements / alternatives to VS. Each product is unique and offers different features, and choosing the best product for you all depends on what your needs and wants are. VS's core features are listed on our website in the "How VoodooShield is Different" section.
One thing is certain... no matter what your security setup is, it will benefit greatly from adding VS's dynamic levels of protection / automatic toggling with risky web apps, and WLC's automatic creation of firewall rules for files that are not known to be safe, among several other features.