Celery powder vs tenderquick = both are "cures" and nitrites. Celery is one of the sources for the nitrites and nitrates in cures. The chemical is the same either way.
Also my Copperhead 5 gives results very similar to RadRob's photos. Stickburner, charcoal (with wood chunks), pellet pooper, and gasser (oh hell no?) all have a different flavor profile though.