246 can be set for hill drop or drilling seed. Model 247 is a check row planter. Old technology.....Less consistant planting depth than later models, incredibly time consuming changing row width compared to unit planters (ie #70, #71) Not quite as adjustable for seed spacing as 70/71. (which can be a major factor in some crops where very close seed spacing is preferred) 246/247's have a tendency to make seed "tumble" as it drops if planting speeds are much more than 3 to 3-1/2mph. 71's are even better than 70's in that regard, generally planting very consistant up to 5-1/2 to 6 mph. Tumbling the seed will effect accuracy of seed spacing, depending on seed, maybe quite a bit. Ground speed is not a big deal if you're planting a garden sized plot, but a major difference when planting a bigger field. Also, 246/247's don't like a rough seed bed. 70/71's shine in rough conditions.
Check row planting stayed semi popular well into the mid 70's for some "niche crops". Nothing prettier than driving past a checked field done right, even if it is VERY much "old school".