Depends on what you are doing.

Disk intensive applications will benefit from the higher transfer rates.

If your current drive keeps up, then you won't see much difference.

When your computer bogs down, is the CPU or the disk. When I
transcode video the drive is busy, but the CPU is maxed our. If I am
sorting a couple of million messages in a newsgroup, the CPU is
loafing along but the drive is maxed out and a faster drive would be
the solution.