The overall score for Sandra's test won't change much, but look at the numerical results in the bottom scolling area after the test. My overall result didn't change much (both were 20,3XX), but even with an old 686A southbridge (ATA66) I noticed quite a difference:
Before (using the 4.34 4-in-1s):
Buffered read: 43MB/s
Buffered write: 30MB/s
Sequential write: 29MB/s
After (still with the 4.34 4-in-1s, put with the patch):
Buffered read: 51MB/s (+8MB/s)
Buffered write: 37MB/s (+7MB/s)
Sequential write: 28MB/s (-1MB/s)
The other bench results (sequential read, random read, and random write) weren't affected.
If you want to check out the difference, you can uninstall the patch and re-run Sandra, making note of the results.