I'd say its how forgiving it is about its environment. some roaches will take a big range in temperature, humidity and diet, others need very specific ranges.
thanks, would it be a safe assumption that a species deemed intermediate just needs a consistent temp. (within proprer range) and a substrate with a certain level of moisture?
I would definitely wait on Gyna centurio with that skill level. If you want to get into the Gyna species, I would start with either Gyna lurida or Gyna caffrorum.