I laid off the weights for a while after tweaking my back a couple of months ago, and it was getting boring, too. I'm good now, but I think I'll stick with strictly the kettlebell for now. Good to try something new. Gotta keep things interesting!
I like the dynamic workout and how it keeps one loose. Plus, with the kettleblock, I can load it up to 70lbs, though I'm nowhere near that yet. I get the sense that with the ballistic movements, that swinging a 15lb kettlebell is more like trying to maintain control of twice that weight with traditional exercises. Plus, the kettlebell movement feels more natural. Somehow, it reminded me of say, swinging an axe or a sledge hammer. Though not in vogue anymore, I'm sure that people had great workouts with heavy weapons training. I'd love it if they had a workout like that! (maybe using mockups, so people don't injure themselves)