I likewise installed the front shelf accessory that Traeger sent. D2 Drive uses a variable speed follower (0-100 rpm) and ingrained software to deliver much better control over cooking temperature levels and give faster ignition times. Traeger's TurboTemp innovation utilizes the multi-speed fan and enhanced software program to aid bring the chamber approximately its target temperature quicker than before. Missing from the 650 is the pellet sensing unit that tells you when the receptacle is runni...