I didn't know they were offering air filled tires for the 900s. I would say as far as damage would go it is more how you operate it instead of what kind of tires are on the front of it. FYI I've ran tweels on the front of my 950m and z glide with the factory tires. I liked the z glide better.I bought a new Z970R, and have had 2 others in recent years. My question is, if I get the air filled front tires instead of the solid ones, will the air filled ones cause less damage to lawns when turning vs the solid ones?