Do I take that as a less then glowing recommendation of the Flexicoil system? 

I've used Case and Deere central fill and do not recall any adjustments or any real difficulty with them, other then the silicone Deere puts around the bolts inside the tank.....when a 1" diameter silicone donut with a 3/8 hole in the middle gets in a tube, it can really present a diagnostic challenge!