I'm using MCTemporalDenoise now. It doesn't blur the image as much. The medium settings are a good compromise between denoise and sharpness.
noise: http://i5.minus.com/i7D8tGzgipztf.png
denoise: http://i6.minus.com/iyhVH7UuT9WjL.png
noise: http://i1.minus.com/ibgaTrrJq0mz4q.png
denoise: http://i5.minus.com/i3EBBLulO7JID.png
noise: http://i3.minus.com/idyxr2wB1hEtm.png
denoise: http://i4.minus.com/iLpwqoxXvVDeD.png