I have an SR22 and love it. Its a great little plinker.
I wouldnt hesitate to pick one up, especially if you like the Walther, which I have as well. The Ruger is far preferable IMO. I wouldnt even consider a Walther at this point.

The only S&W 22 that I would keep over my SR22 is my 422. Love that gun! In fact they are similar in the sense that they are both quite light, and a I tend to prefer a light, short barreled 22.

Happy hunting!