One-Off Patch vs Cumulative Patch

I want to start a discussion about one off patch vs cumulative patch. If I run into an issue in dev (say we are in EAP 5.1.0) and there is no work around, but the fix is in EAP 5.1.1. If I take the one-off patch, I am away from the golden path. If I adopt the 5.1.1, I will have to retest the full EAP. Even though taking the one-off, we should go through the full regression, but most customer only test the patch piece. What is the best way to handle such situation? Also, are there upgrade process between CPs that is less manual.

-Roger