Yes, an M series Leica is the ultimate, that is it is the ultimate in costume jewelery

Less tongue in cheek, they are superb, but a Leica is a totally different camera to a Nikon and you must decide what you want to do with 35mm photography and decide on the basis of that

If you want to use 35mm focal length only then go for the Leica plus 35mm 4th series Summicron