I've had a 550 for about 12 years now and love it. I load three pistol calibers and three rifle caliber and it suits my needs perfectly. I don't feel the need for a 650, the 550 does everything the bigger brother does. I don't mind manually indexing the shellplate, it doesn't seem to slow me down, I can still load 500 rounds a hour when I want to when my primer tubes are full. I've never had a double charge or any problems, my 550 has been a dream. When I originally bought my reloader I considered the 650, but I can't see any advantages to it, the 550 suits my needs perfectly and probably always will. If I were in the market for a new press, I would again go with a 550.