I haven't used it, but I have studied it and its data. Data is poor and lacking velocity and pressure data...yes the powder is reasonably priced and some have had good feed and function others lacked enough to cycle their firearms... http://www.expansion-industries.com/ETR7-PISTOL-POWDER-p/etr7-4lb.htm
I only wish they would publish better info to include true velocities and pressure data to see where it stands.