I alternate with this and my birks. I find that the variation of the shoe helps a great deal, that swapping half way through the day is a good move for my feet.
This spenco insert has an actualy orthopedic logo on teh front of it, in blue and white letters. The package is in greens and yellows, as most of them are. IT is harder to find than the otehr inserts- I found one in a yuppie camping supply store.