Wool is fantastic, but about four times the price of nylon. It is also highly stain and moisture resistant due to the lanolin content. Shedding will be an issue for a while. Both will feel good underfoot, but wool will last longer with proper care.

We foolishly brought moths into our house with an international purchase, but thought we had rid ourselves of issue. We just discovered our wool carpet in closets eaten away and housing webs of eggs. I'm thinking they won't eat nylon.

Wool is a great fiber but it is pricey and in a normal home enviroment where you should replace your carpet after 10 yrs it is overkill. Wool is best as area rug that will last generations or for specific design element. Nylon with the new soft treatment is a much better option. Cost effective and durable. Look at some Shaw's caress series styles. Great stain protection and soffffft. Nylon has a texture retention memory and will hold it's shape well. Follow the proper guidelines for cleaning and you will get the performance you are looking for.

Thanks so much for these helpful comments!