Hi. I'm David from Australia. I fly VH-DXS - a 1979 M20J - and operate it from grass/gravel runways (contrary to the POH). Incidents so far are a bent gear door striking the grass when another pilot ran off the centreline a bit on the landing roll, and a tail strike when another guy crossed uneven ground at too high taxi speed. Both these incidents were from very experienced Mooney drivers. Nevertheless, Mooneys can be operated from unprepared strips but the pilot needs to be very careful on taxi speed and location on the aerodrome. Personally, I have not had any issues in the 5 years I have flown ours on grass, but I ALWAYS stick to taxiways and runways. Prop strikes on uneven ground are a real danger too. Mooneys were designed to fly, they do not like being near, or on, the ground. Hope this helps..