This is my Bosch grass cutter cost rm250+ if not mistaken. Model 220W typ 0 600 821 823 ( strange). You need to train how to use it. Specially how to tide the nylon in the casing.

For thicker grass or dense, this model have difficult to cut as the power not strong enough.

It is not heavy. Why hand numb? Vibration?  You need to train how to use as I said. All this type of grass cutter need to train to use inorder to cut a nice depth. Unless those car type.

The vibration is good. It help you shape your muscle.