Hello,
I presume the reason a ceramic resonator might be chosen over a crystal would be one of cost. I am not aware that the resonator would be substantially less reliable.
I have previously used resonators in old HC705 projects. However, for newer HC908 and HCS08 projects I have generally found the use of the internal oscillator to be adequate for many applications. For those cases where this is not sufficiently accurate and stable, I would then use a crystal.
My production batch quantities are not sufficiently large for small cost differences to be significant, and I generally have more flexibility in the choice of crystal frequency, for example. 4.9152 MHz.
Regards,
Mac