Your list of cons looks feeble to me- but I'm an M3 die hard. Loading and rewind are slightly slower than your typical swing-back, crank-rewind camera. I think it takes me 5% to 10% more time to perform these tasks with the M3. In other words, much ado about nothing. Incidentally, the mechanical feel of these functions is flawless and very secure. Do it a few times and it's just easy.
Resilience? In the eleven or twelve years since I got my M3 (my first Leica), it's been my near constant companion. I've carried it everywhere- sometimes in a bag, or wrapped in a T-shirt; mostly on my shoulder, around my neck, or in my hands. It's banged into other cameras on my person during events; chucked into unpadded (sometimes even non-dividered!) bags with several other cameras and lenses while I run to the next location. It's never been babied. Youxin Ye did a CLA not long ago, and said it was in great shape inside and out.
That M3 finder- it's different than later M's. It's design is simpler, and it never flares. It's great for every lens length (except 35mm...) but I pretty much use a 50mm most of the time; not only because the M3's bright, high mag finder and clean bright lines are perfect for it, but because the 50mm is my lens. Anyway, with top mounted finders, wides are great on the M3 too- and it's the best Leica for 90mm and 135mm. I'm not worried about the finder de-laminating. I know it could happen, but it's not very likely to. If it does, I'll have to get another, or try to repair it, but I don't worry about this.
Since learning to shoot with a non-metered body, I've come to prefer it. The large and medium format cameras I use don't have built in meters either. I feel very confident using a hand-held incident or spot meter to read the light and choose settings; it gives me better information, and sooner- as in before I start making pictures. When I shoot, all my attention is on my subjects and the world in front of me. It's wonderful not seeing lights in my finder or having to think about fiddling with exposure settings when I'm trying to focus on my composition and getting the moment I want.
I'm lucky in that I don't wear glasses- except to see up close. Sometimes I have a hard time reading the camera controls- but the camera is so simple, I know it entirely by feel. If I wore glasses for seeing normal distances, I'd worry about eye relief or the metal eye piece scratching the glasses, but these aren't issues for me.
The M3 is a great camera to keep things simple. It begs me to carry it with a 50mm attached and no other gear besides a pocket full of film. Sometimes I shove an XA in my coat, to have a wider lens. If I'm traveling, I'll add a 21mm, maybe a 90mm, and maybe another body. I've tried the M6, M4p, and Hexar RF; these are all great cameras, but none felt as nice or were as simple and solid as the M3. I sold them all and bought another M3. Now the only M camera I might want to add would be an M2 (or perhaps a Zeiss Ikon; they have great finders, too, and AE which is IMO the only reason to get a camera with a built-in meter); but either of these would be second cameras, to add another body or different features that could be helpful sometimes (like a good body for a 35mm lens...). One body/one lens days will still find me with an M3 and a 50mm lens- I'm basically done.
If any of this rings true, you might be an M3 person, too.
