Depends on your Defense levels.
If you have NO Defense, it'll help a little. But not a lot.
If you have some Defense, you'll see a bit MORE benefit.
If you're just sub-capped Defense, you actually see most of the benefit.
If you're already capped-plus, you don't really necessarily see a lot, though it will help keep your enemy's ToHit floored out as much as possible. But actual benefit is terribly situational.