I have the K-Sun BEE3, and it works perfectly for the application. The heatshrink cartridges are a tad pricey, but at this point in the game, anything less than a cool thousand bucks is lost in the noise LOL!
I'm labelling most of the wires (except things like short jumper wires in switch connectors, etc.), and it's already helped immensely in routine wires, making neat bundles and loops to connect to grounding busses, etc. It's quick, easy, works fine on wires down to 22 AWG, and creates a professional-looking installation.
Highly recommended...
Steve