I use farm works. Played with SMS a tiny bit once. Did not want to learn something all new so I stuck with farm works. I have heard that SMS is a better program for doing this sort of thing. I would like to try grid sampling. Our problem is it takes a hydraulic prob to get into the ground. It costs $100 per sample to hire someone. Trimble SIS has my attention at the moment. I have not heard what it will cost to get it done. I may need to simply build or buy a sampling vehicle and start grid sampling.