I can only tell you my own experience. I shot professionally with 2 LXs and an MX for two decades as a photojournalist for Pacific Stars & Stripes and other newspapers. We shot in very tough conditions - winters in Korea, summers in the Mojave desert, Georgia swamps - you name it. I was a US Army phojo for part of that time. They issued us Cannon F1s, which none of us would use. A few guys shot Nikons, but most of us shot Pentax. The LXs and MX were my workhorse cameras during my days as a phojo at Pacific Stars & Stripes in Asia and 7 other newspapers across the US. They are tanks – once fell while wearing both LXs and the MX running through Tokyo after a shot. Since I only have two hands, the LS hit the concrete and bounced. I caught it and finished the shoot. There’s a little dent on the top plate as the only remembrance.
That said, time has not been kind to the LXs. Both are dead. I looked into repairing them years ago, and was told it would be a minimum of $500. Each.
The MX works as well as it ever did, and I put the occasional roll of film through it. Though these days if I want to shoot film I shoot the Pentax 67.
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Also have had shots published from the Auto 110, a little gem that was my fav until they stopped making Kodachrome 110. The ME Super was used in my early phojo days; it was my first 35mm camera. Got the MX next, then the LXs when I got to Tokyo. Love the Q, but need a viewfinder. Always wanted a 67; bought that one a couple of years ago, and put the occasional roll through it.
Not crazy about modern Pentaxs. Pentaxs were always small, sharp and rugged. The new ones are big and blocky and inelegant. These days I carry an Olympus Pen-F.