I have started making green smoothies, involving raw kale and the like. I'm using my handheld blender, and the smoothies have small pieces in, rather than being totally smooth. I'm thinking the raw kale in particular would probably be more digestible if blended till smooth, rather than in pieces, and I'm wondering whether a nutribullet or similar is worth getting. I'd be grateful to hear from anyone who has one about how well it works and which model is best for smoothies.