I need to put new concaves in my 1688. I will be thrashing corn and edible beans with these concaves. Our corn usually runs about 180-200bu. (wet) at 24% moisture. I've never had any problem with concaves plugging in corn, but have heard of it, mostly on this forum. Are they the same concave only rounded on top of the cross bars? Would they last as long as a standard concave with square edges? I wonder if they would be more gentle on Navy beans? My local dealer recommends the large wire concave with every other wire pulled and the holes welded shut so stuff doesn't stick in them. That is ideal for drybeans. I've always just run the large wire with all wires in. Have I been missing some performance? Any comments will be appreciated. Thanks.