What a difference a week makes. Last Sunday was my first smoke (MES40), three racks of spare ribs. Results.....awesome! This morning I had a late start @ 9:30am. Three racks again and two butts with a combined weight of 17lbs. Put the smaller butt on the top rack, the bigger butt next rack down, then the two smaller slabs and the bigger slab on the bottom. Used the 3-2-1. Set the smoker temp @ 235° thinking if it's 10° off either way I still should be good. Well, the ribs weren't even close to being done.... they're in the oven @ 250°. Last time I smoked I used a cheap oven thermometer for smoker temp. I know it's pretty accurate because I checked it in my oven, unless they were both off it should be good enough for now. However, I didn't go by it this time and it cost me. I still have the butts in the smoker... had to raise temp setting to 275° to get a 225° reading on the cheap oven thermometer (located in middle of smoker) I'm not using the meat probe but, it also reads 225°, so I'm assuming that it's pretty accurate. I'm using a pyrex digital thermometer that I know is 4° off. Bigger butt is at 156+4° IT right now. Anyhow, I need to buy a good thermometer for smoker temps...... it would be nice if the MES was working the way IT SHOULD!