It's pretty sad you have to spend 1500 Euro as an excuse to post another Leica bashing thread...
Of course when talking about build quality the concerns for having the best is partly based on reliability. And when my Minolta goes wrong I know that no matter how old it is, even one made in the 1930's, I can send it back to Minolta HQ for a full overhaul and further warranty on the camera. I doubt you can do that with a Leica.
The SRT-101 is one of my favorites, but, yes, as for build quality the M3-M6 which I'm familiar with are solid high-precision instruments... like a Colombo V-12.
I guess You should look at this "pling" -sound from a small town perspective, where it can be good to let people know that "I'm here and I'm just taking some pictures". Too much running around in stealth mode could earn You a reputation as a "Peeping Tom".
In the "Big City" with all its street photography we have a different situation, an almost silent camera makes it possible to catch people off-guard and thereby get great pictures (often of people You don't know).
So there is a camera for every occasion!
Whether it's a small town or not, whether the camera is noisy or not, people can see you've got a camera and certainly do know when you're taking pictures.
Want to be inconspicuous? Use the camera in your phone.
Want to truly be sure people know you're taking photos? Use a camera on a tripod.
Actually my friend uses tripod and remote control when he does want to be inconspicuous ! He compose a frame and wait for right people to come to the right position in the frame and then he just clicks, nobody notices anything.