Having both a lot of experience with radios and also having the Cardo BK-1 system, I'd recommend the BK-1. It's more convenient, it's better conversationally because it's full duplex (like your telephone), it doesn't require any button to push to talk so you can keep your hands on the bars, it's all contained on the helmet (and not a noticeable weight at all), is rugged, is waterproof, will also work with your cell phone as a headset, can also be used to listen to music, allows the user to have superb situational awareness, and has long battery life.

The only downside is that it is not cheap.

J.