We had Millennium in to refinish our stairs to match our new dark floors. Overall, we are very happy with how they turned out. It was quite a process since our builder gave us natural oak stairs that were sealed. They had to strip them, sand them, stain them and seal them.
While not as nice as stairs done from scratch, I must say, they turned out very nicely. My only complaint is that the base of our metal pickets are covered in sealer which is now very hard to remove. It isn't really visible but it would have been nice if they were covered.