Mooman, I would agree that "acceptability" is attainable in 99% of cases with a slotted saddle.

However "acceptability" is not the criterion I work to on my own instruments, although I fully accept that for large scale manufacturers and professional repairmen "acceptability" is the only economically viable standard.

On an instrument with medium gauge strings, (perfect fretting, easy action, meticulously constructed) , and a slanted saddle, there is no way that the second string which measures .016" gauge, and the third wound string with a core of .012" gauge can possibly play truly in tune if the scale length of the third string is longer than the scale length of the second. I mean, it is a physical impossibility, period. Fortunately for manufacturers, most players ate not too bothered by the discrepancies. But some are.

It is all about economics really. The nice people at Martin are well aware that they SHOULD really construct their saddles differently, but why the hell would they, since they will sell the instruments anyway? Any more than they should complete a decent set-up job before the guitar goes out to the distributor.

Murray