I love to shoot "street" and all that 'decisive moment' stuff really hits home with me. For years I have been using a Nikon FM2 with a 50 1.4, which, when used without an auto-winder, can, in practice, deliver good performance and speed for this, but with none of those intangibles that can be got from using the legendary Leica M. That's not even to mention the speed and image quality of the best Leica prime glass.