Ash bats are generally the most flexible out of all the bat types and create a faster whip through the hitting zone. Similar to a trampoline, when a ball hits an ash bat it flexes down into the barrel before flying off the bat. People tend to believe that, because of this flex motion the ash provides, the bat has a greater sweet spot than most other types of bats.
In terms of the breakage of ash bats, they statistically tend to break more often when jammed by inside pitches. So, take into consideration your hitting style when looking for the right bat for you, as ash bats are great for the experienced hitter that tends to hit for contact.