RO is my go to lump due to it's availability, quality, and price. However 2 bags ago I noticed a nasty burning tar smell coming from my Performer as it was heating up. I found a robins egg size piece of ? that was flaming and giving off the nasty odor.
S**t happens every now and then, but I still prefer cooking over lump!
WSM, Green stainless Performer, Genesis 3000, 2 18.5" Weber kettles, C-G Akorn.