I have an old smoke dragon wood stove made by Englander. It has a 3 cubic feet firebox and loads from the side. I have modified it to try and make it more efficient. I have added more firebrick than it was originally designed for. I added the brick on the end and back. I left the front firebrick only one level high as to expose the front steel plate to the direct heat of the fire. I figured that I would get more heat off the front if I didn't add more brick here. Now to the good part. I added a steel plate in the top of the stove to direct the gasses to the top front of the stove and then they must pass the entire length of the top from front to back and then down 5 or so inches before they exit the rear 6 inch pipe. I insulated the top of this removable plate with a ceramic blanket to hold the heat in the firebox for a hotter more complete combustion. I also installed a 6 inch insulated stainless steel flue liner in the chimney. The liner is about 20 feet vertical from the t pipe on the rear of the stove to the exit so I can get a wonderful draft flowing. On to my Question. I can burn a moderate fire in this stove, maybe 4 or 5 splits weighing a total of 30 to 35 lbs of dry oak wood with the two draft control wheels open one full turn each. The chimney exhaust is perfectly clear and I can even go on the roof and put my nose 2 feet from the flue exit and can't see or smell the exhaust. I can turn the front and top of the stove red with a 2/3 load of wood without overheating the flue pipe. This is +/- 900 degree stovetop temps. The inside of the stove stays chalky white. Is this about as efficient a burn as I can expect to achieve even with a modern stove? Now keep in mind I don't have a secondary air supply for a secondary burn. But whatever is happening in there the fire is pretty darn efficient. My question is, considering what I have done to this stove and having absolutely no smoke at all, Would it be much of an improvement for me to buy a modern wood stove?