As mentioned there is a huge variance in size of individual animals. But on average you should expect bcc to get larger. A 10' bci is pretty rare but a 10' bcc is not that out of the ordinary. As you mentioned individual's very but in my experience Guyana's are for the most part well natured just like South American bci's. Suriname bcc and central American bci are in my expierince typically more defensive snakes.