ya mine larger one from my lfs has a lot of personality and never hides, he swam up my python tube and got stuck when i wasn't looking and he still wasn't scared of me, he jumps out of the water biting my finger if i don't get the black worms in the tank fast enough, he is always up at the top of my tank when i walk in, he is a pig and i spoil him but that is because he won't eat any pellet(trust me i starved him for 2 1/2 weeks and tried 3 completely different brands). Now the smaller ones i got from ken always hide, the pair are blue gene and about 2"ish but they are getting better now, they are starting to come out for food.
But i have also seen other jack that people have had them since they were an inch and they are now 5" and they still hide all the time. i must have been lucky. if you get a jack, look for one that is always out and picking on everyone and not scared of you. Thats what i did and i love mine.