I haven't kept garters since I was a kid, but I do keep kings and bulls now. I'd say my bulls are a little more active than the kings. The bulls are bigger but the husbandry is pretty similar and straightforward for both. The bull's warm sides are kept a few degrees cooler. They're both great snakes to keep! I don't think you'd regret either choice. If you're looking for more of a display animal have you considered a jungle carpet python? They're beautiful too!