Introducing a different slant to this string, for years I've used twin lens reflex cameras (Rollei & Yashicamats) for "street photography".......think about it. Looking down into the waist level finder, rather than the direct vision of 35mm, people tend not to react to you, since they don't realise thet are in frame, and the whisper quiet leaf shutter of a Rolleiflex is quieter than anything else around.

A different approach is needed......just pre-focus on the 6x6 screen..and wait. The larger neg size easily surpasses even a Leica lens, and with the larger area covered by the 75mm lens, you effectively
have (in 35mm terms) something like 40-50-75mm lenses all in one. .........Oh yes, and my excellent Yashica 124 cost me just 99 secondhand 2 years ago.....my Rolleiflex T 170 in 1979 and still going strong.....They are also lighter in weight than many an SLR.

As for Leicas?.......leave them to the antique collectors....they're way too expensive for most photographers.