westfw,
So given 20 years of experience with an RTOS, your coworkers were so frustrated with it that they went to work on a different RTOS ?
Wrong! They didn't work on a different system, they commercialized the open Berkeley system as VxWorks and NASA started using it. CERN picked LynxOS in Europe at about the same time. CERN and LBNL are happy with their systems.
VxWorks now has over a billion copies in products. Several other commercial RTOSs also claim over a billion copies in products.
RTOSs aren't that different in basic functions. Almost all commercial RTOSs have a fixed priority preemptive scheduler. They have similar synchronization/communication primitives. I find it easy, almost mechanical to convert a program from one to another.
You can't choose an RTOS because you don't understand the associated theory. That's what engineers learn in courses like UC Berkeley's EECS 149.
You comments are valuable. I get the message that you will never use a RTOS.
At least you are not like the old engineer I knew who programmed a ROM for one of the first micro-controllers by filling in squares on a engineering pad and then entering them in switches in his home made programmer. I never got him to use an assembler. That was around 1971 or 1972 and it might have been a 4-bit 4004. We quickly moved to the 8008 but left the old EE with his pad behind.