I really don't think it's good unless you build a team around it. Look at it this way. One of the teams I am on had 50 tackles in a game today. Now let's say everyone had maxed helmet crash. 30% of 50 is 15 and each one of those reduces morale and energy by -3. 15 x -3 = -45. Couple that with the morale loss from morale destroying SA's plus the intimidation, and fearsome, you would be one badass defense. Of course you would have to have good builds too. No taking short cuts. It's too bad I can't find a team using this concept :/.