Be careful with crossfit, most of the instructors have no idea what they are doing and can have you doing routines bad for your back. I personally know two people that ended up with back problems from crossfit (each at a different gym).
I agree, however if you hit crossfit after 5 years of power lifting, you are much safe and know what box to avoid. In my current box the injuries rate is near zero because the two instructors are crazy about form. Still crossfit is itself partially risky like many other sports, so also self-regulation is needed, and a bit of luck.
