I liked Asuma. He was tough as nails but he was very kind when ot came to his students. It was cool that he would spend so much time with his team and treat them to BBQ, play chess, etc.
He was cool, but he never seemed all that strong to me, even with the 12 guardian stuff or whatever. from what we saw his battle skills where ok, he seemed to be a lot better with his students then say.... Kakashi though.