How big is the tax break?

Big.  If you have suffered a physical injury, the tax break can increase your net returns by as much as 30% or higher over what is possible through comparable investment of a lump sum.  See this illustration to understand just how much extra money is at stake.

If your injuries are non-physical, the situation is more complex and the benefit slightly less but still significant. Go here for a more information on settlement planning strategies for non-physical claims.