The Lemania 5100 seems to me to be a bit like the Chevy V8. It was designed from the start with ease of production, cost, and robustness in mind. No one at GM in 1955 thought that the small block would still be around today, but it’s still with us (albeit in one form or another) in cars, trucks, boats, etc…
I think it can actually be more difficult at times to design and build something that is reliable down to a price than it is with an unlimited budget. I love it and like it for what it is; a robust, inexpensive (relatively speaking), automatic chronograph movement. As Chuck Maddox said it is the AK-47 of movements.
Eddie