I use the Hair Room. Though not as well as Stewer!

It does tend to look a bit wiry. You can tweak the render settings, though, and get it looking much better.

I use it because sometimes, your character is in a pose that conforming hair just can't handle. (Hanging upside down, say.) And sometimes I add a few locks of dynamic hair to a hair prop, to give a little more life and motion. It's also very handy to add a realistic-looking mane and tail to the Poser horse.

Someone posted a really cool animation using dynamic hair a few weeks ago. He said he was going to post a tutorial, but I don't know if he ever did.