I have exactly same experience. And it is somewhat reinforced by the kind of "software problems" that only manifests themselves on new hardware revision or eve

I have exactly same experience. And it is somewhat reinforced by the kind of "software problems" that only manifests themselves on new hardware revision or even production batch. And the causes range from wrong chip assembled in production (sot23-6, same package marking, but dual jfet really does not work as replacement for LDO), through various signal integrity issues ("how did you determine, that this makes 100R mictrostrip?" "It looked right and makes the board look right", somehow the "right-looking" diffpair on 6+ layer board does not work on 2 layer backplane) to real sillicon errata that either can (MSP430G-series USCI interrupt handling, you will not even trigger that when using TI provided sample code) or can not (Microchip's various pin routing issues, some Intel Atom erratas and such) be sanely worked around in software.