I shot both on the same day. The Ruger seemed a little better made, and more accurate than the Walther.
I think the Ruger was cheaper too. Seems like a slam dunk decision to me. Unless you really love a particular brand.
I did have a couple failure to ejects with the Walther, but I think it was just holding the gun too lightly. There isn't a lot of energy to work the slide/eject.