I've tried electric knives, including those from Kelley, and now use the water-heated uncapper from Cowen. I would not go back to electric. Any chain uncapper does a better job than any knife system at uncapping because the chain uncapper will get all the low spots. However, the chain uncapper also pushes wax and other inpurities into the honey and it must then be removed by either settling (a long process) or filtering (which I prefer to not do). I suggest spending the money and getting the water heated knives.
But consider steam. I know nothing about steam, except that the even heat provided is admirable. Dadant sells a neat little steam jenny.
Lloyd Spear, Owner of Ross Rounds, Inc. Manufacturers of round section comb equipment, Sundance Pollen Traps, and full color custom Honey labels