I tried operating the stick blender with 2 hands and it was a disaster. Holding the "lock" button with one hand and holding the "Low" button with the other hand, suddenly the mixing carafe became unstable and the smoothie I was mixing splashed all over the kitchen.
I HATE this feature. My hand is not strong enough or even large enough to operate the thing with one hand.
I called Cuisinart Customer Service and the agent said I should return the blender to the store and exchange it for a different Cuisinart model that doesn't have this feature, but he couldn't tell me which of their stick blender models don't have the feature. I then emailed their customer service and so far they have not answered my question, they are just telling me it's a "safety feature." Whoever designed this stupid thing is a complete idiot, I'm sorry.