Ok, so here I am answering my own question for anyone from TFP who may stumble upon this thread. I bought a Coverstar autodrain off ebay this winter from a company that was not able to install it for a client. The client did not have enough clearance at the end of his pool for it to tuck in. It arrived with a few scratches and dings, but looked basically new as described. I successfully tested it over the winter in my bathtub.
What coverstar did is incorporate an auto sensing marine bilge pump in a heavy metal enclosure that your pool cover drags out and then drags back in. The swing of the pump which is attached to a long aluminium arm that is limited in its arc by its attachment bracket. I think the weight of the enclosure ensures that is will weigh down your cover in the spot where it sits so that water flows towards it. The product seems well constructed. The aluminum supports are solid and well built. As long as the bilge pump works it should operate like a standard rhule pump.
One problem-- Which I thought might be a problem for me. Won't work for me in my pool. I have a kidney bean shaped pool with a rectangular cover. In my configuration the gizmo has trouble climbing over the pool lip and I did not install it for fear of too much wear and tear on the cover. Because my pool deck lays inside the cover it would have been tight for the bend in the swing arm to avoid scraping my cover as well and would have required a very high water level.
So essentially, It it seems like a sturdy product-- but not designed for my particular pool. In the videos I see it seems to do well in a rectangular pool designed with a coverstar cover from the get go. So for now it is back to the diy Rhule cover pump.
I will try to resell my unit on ebay-- if anyone from TFP sees this and wants it I paid $290 plus shipping and would sell it for the same through a paypal transaction. Pm me if interested or if you have any questions.