In a couple of months it will have been 4 years since I got my BDS. I have no idea of the number of cooks (sometimes I have both of them going at the same time), but I have never used a drip pan or a heat shield or anything (except when smoking cheese over a tray of ice, but that was to keep it from melting)
My briskets, butts and chicken come out too good to ever try a drip pan with those, but fatties can really drop a lot of grease into the coals, and the clean-up is the worst after cooking a load of them.
This afternoon I was cooking 6 one pounders for work tomorrow and I used a drip pan on the lower grate. I have 6 or 7 inches between grates, so the smoke was able to circulate really well, and even though some drips of fat got by the pan, it did capture a lot. A couple of cups anyway. The real test will be the flavor tomorrow.