Best bamboo needle cutter and why ?

[Inigo]

Very good.
For Bamboo, you can get cheap large bamboo canes in gardening stores, but you'll need one that is old and dry enough. I found mine in the trash bin! Also you can take bamboo from many kitchen and home stuff which they're now selling in marts, etc, as it seems to be fashionable: cutting pads for the kitchen, trays, etc made of bamboo... I've not yet tried these. But I've tried Chinese bamboo eating sticks... Ha, ha
In my opinion, the outer shiny hard shell or skin is not absolutely necessary. It is harder, yes, but I've also had good results with needles cut from other parts of the bamboo. If the fibres are hard, straight, tight, parallel and strong, better if they're old and dry, you can have good results anyway. And besides this, sometimes the shiny outer skin also has its own problems... Depends strongly on the type of bamboo you're using... Highly random until you learn by trial and error to identify the bamboo that will make good needles.
I don't use any treatment except let them needles dry, once cut out, by spreading them on a metal tray placed on top of the heater, then store them in a dry box or pot, with one of those moisture absorber granules bags.

[pianolist]

As many have written, I use an L&H. I have other styles, the scissor type, the Victor guillotine type, but the L&H consistently leaves a nice point.

[Inigo]

That's true for the L&H, more acute point angle than with the Victor type cutters, or the HMVs. These leave a good point, but the more stepped cutting angle leaves a thicker needle, more robust, louder sounding, more stiff... Depending on the record played, I generally find this type of point less durable than the thinner one provided by the L&H cutter. In the end, if you look at the front triangle which runs on the groove, the L&H is narrower, and sure this is the reason to the more treble sound, more equilibrated. You're reading the groove with something that resembles the groove cutting needle, or the Shibata, with the sides of a triangle running on the groove walls, like a V. So if this is narrow or wide affects the sound, and the wearing speed. Although if you examine the point of a worn bamboo needle, it develops a plane surface where the point was.