Not really. He does start out slow, but gradually gets better till about lv 40 when things will really start to take off. And even after the... nerf, he still deals formidable damage. It's just that he is 1) inheritely slow in general, which puts you at disadvantage again a very large mob or fast enemies, and 2) being a risk-taking burst-damage specialist ain't so easy when things in higher stages can easily wipe the floor with ya... not to mention that there aren't much you can do while not transformed.
ADDED: BTW, try not to bump a really old thread...