Hey bud. He's cool as a cucumber, never struck at me and I think I've heard a total of two hisses out of this guy in over 2yrs. I expect he'll likely reach 6'+ but I'm not rushing him to get there. Slow and steady wins this race.
They're a bit less forgiving of errors compared to BCI from what I know, but I've never kept imperator animals. Just this guy and my Argentine Boa currently. I will say that if you do the proper research and know how to read your critters I've found him to be one of the most manageable snakes I've kept. This boy is definitely a bit more grabby/clingy when handling compared to my BCO but I'm only collecting observations from a sample size of one example of either species.
Regardless, love the hell out of them both.