In my experience, the Alpas were thoroughly reliable.
I used them because they not only had superb "own label"optics, -i.e. Kern, Kinoptic, Angenieux, Kilfitt and Schneider, engraved with -Alpa- and tested at their factory in Ballaguies in Switzerland, but because their short lens-mount to film-plane distance made it possible to adapt all other SLR optics.
No idea of the beauty of their innards, which have been praised here, but my Alneas, the 9, 10 & 11 always kept working.
The last Leica Rs and the Kyocera Contax had brighter viewfinders (and also very good lenses) but were stuffed with more accident-prone electronics. Pignons avoided those by going broke at the right time to preserve their reputation the (surprisingly rare) japanese Alpas excepted.
p.