After selling my RT-680 to a friend a couple of years ago and getting a Firecraft Q450, I've bought a Rec Tec RT-590. I think the Q450 worked better as a grill especially with the ability to open the door on the drip pan and have an open flame. I never could duplicate the ribs I was making on my Rec Tec though. I have eaten off of my old unit since my friend has it and it reminded me of the food I used to make. I can't explain why there would be a difference in the way the two units cook at lower temps, but to me, there is.