The only ything wrong with kettlebells is the price and the way they have been marketed stupidly as the be all and end all of training. they are an effective tool that an athlete can use to improve there training. I personally follow my own version of the faq 3 day routine but before this i was doing a double kettlebell 5x5 and found it very effective. While i train differently now i don't see why they deserve all the flaming personally
