I installed my IQ-4 kit last week. It takes about 1-2 hrs. working slowly and carefully and is pretty straight forward. The instructions are pretty good and complete except I drilled a new screw hole to mount the temperature probe. You can mount it using one of the existing screw holes, but the probe would be crooked. While I was working on the FEC anyway, I vacuumed it out and cleaned the racks and drip pan. I did my first cook using the new controller yesterday and it held the temperature within 2 degrees of its setting. I cooked some chicken halves at 320 degrees and they came out perfect, with a crisp skin. I am looking forward to trying a longer, more complex cook. Some people have mentioned using the cook and hold feature backwards, that is setting the cook temperature lower to smoke the meat and the hold temperature higher to finish the cooking. That sounds like the ideal way to do an overnight cook.
I think I am going to like the IQ-4 controller. Maybe I can sell my old Traeger controller and draft fan to someone who is staying with that controller and wants a backup.
BTW - I was concerned that the cover would not fit over the new controller, but there was enough loose material in the cover that it still fits fine without modification.
Mike