That is a great looking sandwich!
Being a NYer, I had never had Tri Tip until a few years ago when Big Brother Smoke, Steph Franklin came for a visit. We were cooking the Battle of The Brethren and I made him cook some for the pot luck that night. I have been hooked ever since.
What did you use to rub them with? I'm using Steph's Simply Marvelous Peppered Cow on them these days in a mesquite fire. Yum!
"What sort of people are these charcoal masters? They behaved badly and were unconcerned with appearances. Their hair was long and unkempt and their clothes were wrinkled and old. They drank beer to and from the crab house and they made rude noises while we cooked." Tao of Charcoal