Now Don I know where you are at Tri-tips can be a bit pricey but in California they are plentiful, always on sale in the summer, and a California staple.
I have a method that Jim(Jim's Barbeque) told me about where you cook the Tri-Tip like a brisket on low until the internal temp s 200F. It comes out moist, tender, and delicious. I call it Trisket. I thought Jim was crazy until I gave it a try. Of course I used $2lb Tri-Tip so it makes it easier to experiment.
In California good brisket can be a bit pricey and actually I can get Tri-Tip for less many times. Plus they will cook faster and come in a more manageable size.
So if you are interested I will smoke the Tri-Tip at 225F to 140F internal temp then tightly wrap in foil and finish at 260F until the internal temp s 200F. Let it rest then slice across the grain. You can also stuff it with garlic before smoking.