The rangefinders are excellent and very easy to focus with, the viewfinder is quite tiny but certainly ok if you are not one who is concerned with perfect framing. My Leica II is almost perfect for daylight work, and it is very compact and very reliable. My favorite way to pack this camera is in my shirt pocket and any external viewfinder gets in the way.

Like anything else you do in life, using the built-in viewfinder really does get easier the more you use it.