unittest vs py.test?

[Roy Smith]

I've used the standard unittest (pyunit) module on a few projects in the 
past and have always thought it basicly worked fine but was just a little 
too complicated for what it did.

I'm starting a new project now and I'm thinking of trying py.test 
(http://codespeak.net/py/current/doc/test.html).  It looks pretty cool from 
the docs.  Is there anybody out there who has used both packages and can 
give a comparative review?