You compared cutting drilled beans with a flex to 30" rows with a row crop header. The question was about cutting beans in 30" rows. First off, were both planted at the same time and fertilized the same? A day can make a big difference. Secondly, drilled beans will set pods higher, therefore reducing the chance of cutting pods in half or even leaving some on the stem.

This year I'm running two combines to get the crop in faster. Both 8820 TII. One with a 8 row Row Crop and the other with a 22' flex. I can tell you from experience that the flex will leave more beans on the ground. Head is adjusted to cut as low as it will go and the reel is going same speed as travel. Could not tell you the diff in bu. as I have not weighed them off, but just by looking in the field, I see more beans on the ground with the flex than the Row crop.

Let's say for argument purposes that both heads are a wash. I would much rather cut with a row crop head. More speed, better ground hugging, no chance for rocks, more visibility,etc..

PS: Take off the skid shoes and replace them with disks and your RC header will cut even lower and won't push dirt in loose ground.