A great deal has to do with what you're planning on seeding into the ground, what type of soil you have, and what you have as far as a tractor.
ie forage grass (pasture/hayfield), lawn, cereal grain crop, corn, deer food plot, ect....
sandy loam, gumbo clay, rocks, roots, ect.....
small (compact), larger "AG tractor", ect.
A few more specifics and you'll stand a better chance of getting ACCURATE and specific answers.