Paul,
I wouldn't be too sure about having no problems. Just think about the different way latches are programmed: latch and unlatch (Allen-Bradley), keep (Omron, set and reset (Siemens and several others). Also retention can be a real problem: is it the instruction (Allen-Bradley) or the memory location (Siemens) that determines retention? I agree that the are not mountain-high, but they still exist. Besides that I dn't know in what bin the GE Fanuc falls exactly.
Kind regards,