Got the new IQ120 this week; just did a quick trial run doing some smoked wings on my Brinkmann Trailmaster LE (COS) with split oak.
Set-up: It is easy to set up, and I was surprised with the number of pretty advanced features, including lid open and ability to program a different pit temp once the food hits a certain temp. Programming your desired temps and alarms are pretty easy. Also has variable fan speeds, alarms for pit and food temps.
During the cook: I set the temp for 300, planning on a two hour cook. However, the fan shut off at 280, and then would only run 2-3 seconds then shut off for about 30 seconds. It never hit 300; I gave it about 20 minutes, and I re-set the pit temp for 320. As soon as I did that, it held between 298-304 the rest of the cook. I've never had my smoker hold a temp so steady, and throughout the entire cook. I lifted the lid once to flip and rearrange the wings, the lid-off feature worked as advertised - but the fan doesn't kick back on immediately when I close the lid. Might have taken 1-2 minutes for the fan to kick on.
Smoke: When the fan shuts off, I was getting much thicker puffier white smoke than I like. That eased towards the very end, so maybe I just needed to make a bigger fire; or let the fire burn alot more before starting the cook.
Overall: Works as advertised; and I'm pleased with it - I just need to learn how to keep the thin blue smoke going when the fan shuts off. Temp held rock steady, even though I had to set it 20 degrees higher than my desired temp to keep it there. I also used less wood, even though I was cooking 50 degrees higher than I normally do.
Hope this helps. Doing some ribs tomorrow, planning on doing a video review.