Here's the good: Its cheap. I paid $50 used. I had 2 SB-800s before and I don't use flash enough to justify it at all. It works, its iTTL so it talks with the camera like any Nikon flash.
The bad: Its not as good. Mine has inaccurate exposures some of the time, and its generally not as nice looking. I consider it far above the SB-400 and about on par with the SB-600, but at 1/4th the price.
I generally bounce or use a Sto-Fen diffuser, so its not a big deal that the exposures are kinda off. Its super easy to fix in post. Well worth it if you get it cheap