I don't see it mentioned but you completely filled the tray and all the pellets were used up, right? I average 12hrs per tray so for 15hrs, the tray should be total ash. While I agree PM blend is milder, there is hickory in there as well as maple and should be noticeable but maybe not as strong as 100% hickory. As was already said, if it was served same day and everyone hanging out near the smoker, they could very well be nose blind too. I never eat same day I smoke... Only other thing I can think of is that some people are accustomed to charcoal flavor in smoked food (I am not) and if that is the case, there are charcoal wood blend pellets that might help but have not used them myself. Hang in there, you'll figure it out!