I've tried it in 3 fields on 3 blocks of ground (specifically) and found where it indicates 200-300mm accuracy it's been 200mm...but when 50mm it's been 100mm, and that's measured using a fibreglass tape, so I alter the working width to overlap 100mm. This is in NI in an area where my Trimble R10 RTK has quite poor signal, so I'm very surprised. Also used effectively in West Sussex to map tramlines @24m for carting grain/compost and no issues. Does my job, and for the money I'd hope it does many Others. I could package it.and send to you for a demo?