Onion agencies

Hello folks. I got the impression that any cutting wrinkles the onion more or less, releases the juice, you only cut it gently with a sharp knife, without loss of juice ... Just yesterday, the men tested various cuts on TV, so we concluded that it might be worth buying such a tool for us and have it at home. Viewed some onion choppers reviews. Guys, advise if you have such a device at home, how often do you use it?