To answer the OP's question: body chemistry varies from person to person. For instance, some people are more to sensitive to perique than others, so you're bound to see a difference in reviews regarding its taste level. That would also pertain to other tobacco varietals. As for why some say a particular blend is moist out of the tin when others say it is dry, well, I've experienced that with several products a couple of times, i.e., Orlik Golden Sliced and Dunhill Navy Rolls. Usually, those two are consistent in their moisture content, but I got dry tobacco from each a time or two. Usually, Dunhill London Mixture is lightly moist, but I had one that was fairly dry. Things like that may occasionally happen.
Many years ago, I noticed inconsistencies in Balkan Sasieni regarding the spice level from batch to batch. I understand that's not true any more, but it did happen. Probably a lack of quality control.