I made this for the 2nd time this weekend and it is consistently the best mac-n-cheese that anyone has ever had.
I added some fried up bacon chunks and it could have used some more but I was in a hurry.
Note to anyone who hasn't tried this yet - don't get caught up in the specificity of cheese types. Cheddar dominates the flavor as does the smoke and - in my case - the bacon. But the firmness of the result is awesome. I served it at an outdoor party and it tasted great hot, warm and cool at the end.
BTW, I set the Smokin-It at 230 degrees and it cooked for about 90 minutes. I'm pretty sure 15 minutes less or 30 minutes more wouldn't have negatively affected the flavor. I made 3 batches - 2 on 1 shelf and 1 above. All 3 had different amounts of brown on top and all 3 were awesome. I put in some hickory chunks but there wasn't a distinct hickory flavor - more of a general smoke and toasted cheese.