For those of you that market garden and would like to have a precision seeder, take a look at the units at this url. http://www.stanhay.co.uk/8xx.shtml I have two rows of the 840 units. They are extremely accurate and take very little extra seed to "prime the hopper". The 820 push units would be great, and I suspect better for most of us than the 3 point implement style. To provide accuracy the metering system is a punched hole belt. The belts are punched to the very size of seed you have, and to specifications as to planting distance between seeds. You can even have a belt punched to plant 3 lines of seeds side by side such as for letture, radish, or carrot. The 3 line belt uses a different ground opener to distribute the seed into the three tiny furrows. They aren't for the feint of heart as they are expensive. If you hire labor to thin plantings, they would save that job due to accuracy, and would pay for themselves over time. Each seed variety needs a different belt which also adds to the cost. If you have a market garden---take a look. A once in a lifetime purchase should last forever with care. The units can also be used on a toolbar on a two-wheeled tractor such as a BCS.