What makes manzanita wood the best wood for bird perches?

 
What makes manzanita wood the best wood for bird perches?
I've heard this somewhere, and I'm not even quiet sure it is the best wood for birds! But what is it about this wood that makes it one of the best (or the best) wood for bird perches?

answer:
Well, Manzanita is very hard and durable. It can get slippery with wear though so some people dont recommend it for smaller birds. I forget who told me this, but they were talking about Cockatiels, I believe.

This company has a few claims about why its so great:
http://www.parrotsnow.com/manzanita.html

Hope it helps ... I'm really not sure either, some of the prices for larger play stands are ridiculous though!

Alexis