I burned Blashak for several years, until my dealer switched to Reading. I guess it was a real pain dealing with the Blashak people. Anyway, Blashak always burned very well, and I was happy with it. The first two years of burning Reading were questionable. The coal was generally very wet and had a lot of fines. This year, however, Reading must have done something different (better!) with their quality control. Each bag of coal has been really good. I burn nut coal and the sizes of the pieces seem to be really consistent. Reading was also known to have rocks in their coal. Not that I've found, at least not this year. I have no problem getting 12-14 hour burn times with the Reading I have for my Yukon Eagle wood/coal furnace.
Side note. Wind chill outside here in the U.P. of Michigan is -16degF. Inside our 2500sqft ranch, it's a toasty 74degF! Gotta love coal!! We also have a propane furnace, and with propane being relatively "cheap" at $0.90/gal, I'd have to burn a LOT of propane to have the same warm comfort level in the house. Wife loves it, because she's always feeling cold, well, not anymore!!