I predominantly smoke cobs and have a couple I've smoked daily for the last 8 years and they are still going strong. Keep them clean and control the cake and they will last a very long time. I wipe out the inside of the bowl with a paper towel after each smoke and run a pipe cleaner through the stem. I do that with all my pipes though. They will still build cake, especially if you smoke a lot of burley blends. You can make pipe mud using cigar ash and water and fill the gaps around the stem inside the bowl to make them last even longer and easier to clean out.