I keep adding more and hotter peppers (dry, sauce, extract, fresh) and I can never get anything really spicy. I've even tried ghost peppers. No matter how spicy I make either marinade for jerky or brine for ham, I can't get the meat to really hold the taste.
Of course it is spicy to some people but it seems like there is only a hint of the spices left when it comes out of the smoker. Smoke flavor on the other hand comes out very strong.