That is yet to be seen... It did appear to be dropping seeds pretty well. The texture of the dirt here is pretty fine & soft. The Earthway does a decent job, but has a tendency to dive in, or if a small clod gets caught in the covering chain, it's like a wheel chock.
I set a 3/4" board under the drive wheel to set the planting depth, and the only place I saw seeds not covered was at the end of the row where I picked it up to turn around.
Last year was the first time that garden had been turned over for 25 years. There were many small chunks of sod, that would catch on the planter shoe, and didn't work do well. Seed spacing was good, just kept having to stop & clean. This year it sailed right through, covering & pressing the seed in well.
Last years sweet corn seed was pretty small, probably due to the drought year before. So I was getting 2-3 plants per hill. Not a problem, as that's what we used to do anyway. I also used the sweet corn plate to plant the Roma green beans. I tried the bean plate, but too small. Did a test drop in the shop first. The bean/pea plate would work well for beans like Pinto, or Navy, and small peas I'm guessing.
I used my Earthway to plant my carrots, as I planted two varieties in a semi-hilled row. They were only about 20' each, so just less work using the Earthway for that.
I will post pics when things come up to show how it did.
Right now, there is one of the DB field planters on ebay, in PA. I'll post it in the thread where the fellow had pics of his. Or I'm thinking it was on this DB forum. I'd consider it if the fellow would ship, but it's pickup only, and too far away. It's starting at $99.99, so saved it to see what it goes for.