I see Roastmasters also offers it. Control of drum speed would be interesting, but the manual mode for heating elements is more interesting to me, I think.
Yeah, the manual mode of the 1600+ is what sold me on the behmor. It was the one major criticism of the regular 1600 that held me back from buying it. Of course, it's still far from a perfect machine, but for the price, I don't think it can be beat unless you're willing to get a little crazy with some DIY stuff.
I haven't adjusted the drum speed during a roast. It just toggles between the speed it normally runs at during the roast and the slightly higher speed it normally runs at during cooling. Maybe it would be more of a concern when roasting 1lb batches, but i stick to 1/2lb and 1/4lb. Or maybe I'm missing something entirely