Here痴 a couple of things from my experience with both.
Diskbine Knives are cheaper than a cutter bar and easier to replace. Cuts faster and I have never plugged one. When something does go wrong, it gets expensive very quickly. Cutter bar or gear boxes can go into the thousands.
Haybine Slower, more prone to knife and guard damage. Much cheaper with major repairs. Better with down hay, can be more gentle on leafy crops.
Having used a disk, I hope to never go back to a sickle bar.
One other note, I myself after having used a disk mower would never use one on a tractor w/out a cab. Or at least have a shield made that goes between the tractor and the mower. I have a neighbor that I help a lot, and he switched 5 years ago to a disk. His brother, who has had disk mowers for about 10 years before that, was the one who told us about the safety issue. If you hit a stone just right it can come out and can go up. We groom our fields like a lawn when we seed back (woodchucks don't seem to care). We also replace the front curtain as needed. In 5 years mowing about a 100 acres a year 2-4 cuttings per season we have had 3 stones hit the cab. One time breaking the safety glass, 2 other leaving chips in the glass. Very glad the glass took the hit and not me. I know people mow with these without a cab, that is there choice, not mine.
