Also is there a difference in the shutter sound due to one of them being fully mechanical and the other electronic ?

>>2872614
How fast is your photography? The M7 has auto exposure while with the M6 you have to set the shutter speed yourself. I wouldn't worry about the battery dependancy. You can still use 1/60 and 1/125 without batteries on the M7.

i'd go with the m6

>>2872614
M7 for A Mode Auto
M6 for metered M Mode

all the other differences are minor to non existend

if you want trve mechanical Leica get an M2 or M3 (M2 if you like 35mm lenses)

>>2872614
>does the M7 still retain that mechanical feel ?
>>2872618
>Also is there a difference in the shutter sound
if these are your main concerns for spending thousands of dollars, I think there might be better ways to spend your money.

Watch out for the M7.
It is hard enough getting an M6 repaired and the M7 parts are more scarce. There is more to fail and I would just worry.

I'd get an MP if you have the money for it instead of the M6.