Originally posted by Adam The first thing to come to mind is the ME F...that held them back several years in the AF department.
How does being first to market (1981) qualify as holding back. It was my understanding that Pentax made a measured manufacturing and marketing decision to not pursue AF beyond the single model. The same was true for Olympus, Nikon and Canon during the same period. By 1984, no one was making AF 35mm SLRs. Eventually it was Minolta that built a workable PDAF* camera (1985) with the result that all the other players were caught a little flat-footed. Pentax released its first PDAF body (SFX) in 1987. That same year saw Canon and Nikon doing the same.
If the Pentax AF history is to be faulted, it would be in regards to not being competitive with second-generation PDAF systems.
Steve
* The early AF 35mm SLR bodies all used some form of contrast-detect autofocus.