First off, I am 5 years out of a university degree in Actuarial Science. This makes the casualty side require more statistical analysis, but means the numbers on the life side have more statistical credibility.
Disability insurance is to some extent a middle ground.
The life insurance side is currently more into investments. Life is longer term after all, but this is changing, and the casualty side is working on the investment side. Many people view this as big growth for actuarial, and view the life side as being more prepared. The casualty side is newer, and less developed. The casualty side has more growth areas, and opportunities, and is likely easier to find work worldwide.