I smoked some Baby Backs and a Rack of Spare Ribs Sunday. The Baby Backs were about 2.5X more in price than the spares. I cut both into halves so total of 4 1/2 racks that fit on three shelves in my CS45. I rubbed them with yellow mustard then coated with a combo of "Slap ya Mama" for some heat, then "Butt Rub" for flavor. They sat about 2 hours then into the smoker at 225 with one chunk of CS hickory. For some reason I placed the baby backs on the lower shelf, in hindsight they should have been on top. They smoked for about 2 hours then I switched the BB up top as their temp shot up real fast to close to 180, not a lot of fat on them. I continued till I reached about 180 in the spares (3.5 hours) then wrapped all in foil until about 5 hours had passed, then onto the gas grill for some burnt edges. I did coat them with some Sweet Baby Rays and Brown Sugar prior to grilling. They did come out exceptionally delicious but for sure the spares were way more tender and juicy than the BBs. I don't think I'd waste my money buying more BBs when the spares are so much cheaper and tastier in my opinion. Plenty of leftovers.