Been using a couple of the mods that help with performance and I was wondering if any of these were redundant or didn't work well together.

- Oblivion Stutter Remover
- Windom Earle's Oblivion Crash Prevention System
- Streamline
- Operation Optimization

Do not use Operation Optimization. This link and the site should help answer your questions: http://sites.google.com/site/oblivionpoinfo/walkthroughs/baininstallguide/part-ii-before-installing-mods. It is okay to use WeOCPS, but try to make a stable game without it first. If you are unsuccessful, then install it. It is a safe mod for many, maybe even most, people, but it covers up crashes that you might be able to do something about.

Useful website, thanks