Andy from Ugra CNC mentioned I should go with their air-cooled spindles since they have angular contact bearings and the water cooled ones have radial bearings. In the end for routing wood and a bit of aluminum cutting which spindle should I go with? I personally like water cooled since it's silent and nothing can get into the spindle, but if it's significantly better to go with air cooled then I'll go with it. Andy merely mentioned one is better for harder use so I don't know what that means. Since I'm not a machinist I don't know a lot and reading online about bearings doesn't give me a good grasp of what to think.