I kept GT and JD together and separately for many years. The ultimate size of GT and JD are about the same, maxing out at 10 inch for males. In term of aggressiveness, it depends on the strain as some GT will dominate over JD, while others will be submissive. In term of personality, I prefer GT over JD as GT are outgoing, and JD are timid and some will hide all day long. I have never kept Carpintis, but since Carpintis ultimate size is larger, I would assume that Carpintis will grow faster than either JD or GT. Also, I've never seen Carpintis that is timid.
