some of those type flange and curve arrangements help create the airflow that lifts the cuttings. I don't know about that one, the photo is too dark, black on black etc.. My Toro Recycler has something similar and it helps with the recycling of the clippings or lifts them into the basket. Some of the newer blades are better at that than the older ones. i would think the later style would be safer too, making it less likely a blade could crack or bend at the mounting point. What would the point be, using an old blade that was laying around than buying a spare? I have a Toro Recycler that I sharpen a couple times a year with a file and stone, it is almost 16 years old and I have yet to need replace it with the spare I bought back then.