I used a 3 point spreader for several years and have also had several box store pull-behind spreaders over the years. No comparison. The 3 point runs off the pto rather than from the rolling of the tires on the little spreaders. Instead of a coverage pattern of several feet, a 3 point spreader will disperse seed or fertilizer over a much wider area (15-20 feet for seed; up to 40 feet for lime pellets, fertilizer, etc.).
The pull-behind models - at least the ones I've seen - are cheaply made and do not hold up to heavier material. Conversely, the big 3 point spreaders are maybe overkill for a couple of acres, however I prefer their reliability, and they make covering 2 acres a quick, easy chore.
The good 3 point ones have stainless steel components for corrosion resistance. Even so, cleaning them thoroughly following use and storing in a dry place will keep them in top shape.