I love tri-tips! Try it with oak some time, for that "Santa Maria" bbq taste! A couple of quick recommendations - put your water pan on the bottom of the smoker, up against the smoke box. It will heat better, and be a better heat-sink for those temp swings. Also, when you "low and slow" beef to medium-rare or even medium, throw it in a 500+ degree oven for a few minutes after smoking for a "reverse sear." It won't cook the internal meat any more, but quickly sears and caramelizes the rub on the outside. Take it out of the smoker and wrap in foil to rest while the oven heats, then throw in for 5-8 minutes. Wonderful results!