In my line of work I need a knife I can open and close with one hand, usually the other is occupied and opening a knife with your teeth isn't good. When Kershaw came out with "Speed Safe" models I was in hog heaven! Open and close , I don't know if they are true automatics , but they work just like one. Index finger on the little button on the back of the blade and she springs open just like a switch-blade. The opening mechanism is simple , strong and easy to replace, Kershaw will send you the spring at no charge.
I own about 12 different models and have worn out one spring.
My favorite for dress is the Leek, for work The Volt II and OSO Sweet II .
I like all the Kershaw Speed Safe knives, they come in many different models, check them out.
Gary