Used a Kelderman a few years ago,keeps the corn feeding in.Makes for a lot less backing up and or cleaning the head off.Word of advice,get it early before the stalks really rot.
I got a Bish reel last year and really like it. It went on easy and I had no wrapping around the reel itself. You control it with your reel speed control on your combine. Mine stays out of the way of standing corn so I can leave it on all the time if I want to.