I like kettlebell training and I've done Anthony Diliguio's "Enter the Kettlebell" program designed to accompany Pavel's book of the same name. What I liked: it's a short intense workout that leaves you feeling accomplished. I'll switch over too it at work for a few months when things pick up and I don't have time for a regular workout. It doesn't require much equipment, only the kettlebell and a pull up bar, and a jump rope if you want to follow the workout to a T. Diliguio's book is great it lays out every step of the workout and doesn't leave you with the questions some other programs do.
What I didn't like, I didn't notice a lot of improvement in performance or appearance. I'm already in pretty good shape always follow some workout regime be strength or bodybuilding focused. The workout is structured to get progressively more difficult and I didn't assess how well I could do the beginning phases of the workout as I approached the end. I assume I would have been able to do better. My point is in my boxing training and other martial arts pursuits I didn't notice any significant difference. Maybe I was just pushing myself harder as I improved and thus didn't notice much, maybe I'm just oblivious. Not that anyone here cares about aesthetics or how they look shirtless but I didn't notice much of a change in my appearance either for the better or worse. The workout gets boring after several weeks and its hard to stay motivated, and that's usually not a problem for me.
In short, I'm not a fitness expert but I like to workout. Kettlebells are good and worth a try. I used the recommended 35lb kettlebell. I normally lift weights and usually focus on the "big" compound lifts. I didn't venture outside of the exercises in aforementioned book. I've looked up kettlebells before and people have these amazing religious experiences with them. That's probably not gonna be the case if you usually workout. You might be sore after the first week or so but the body adapts and that's soon gone. They are nothing special just another tool to condition and train your body. I think they're best to use if your time is limited. If you're used to proper lifting technique Pavel's videos can get you going. If you're not used to lifting you might want to find proper instruction, not that it hurts even if you are a little more experienced. I didn't injure myself with them. When I injured my shoulder with free weights I started the KB workout again and was able to do it with the (mild) shoulder injury and my shoulder healed as I progressed through the KB program.
They make me feel gross when my palms start to sweat.
