Call me old fashioned, but I've never seen a "plastic" stock that I liked. As for the "more stable" argument, a quality timber stock, finished properly and with the action bedded correctly and barrel floated will be as stable as any other stock material. If you are inclined to bash your rifle around and use it as a walking stick or shock absorber when you get around the bush, by all means get a piece of plastic. No sense wasting a good piece of walnut on someone who don't appreciate it.
You won't find plastic that looks this good