I live in California and grill TriTip all the time, it's my favorite go to and runs circles around stuff like brisket. It's Easier, Cheaper, juicier and more flavorful.
As for the Wagyu, that's a bit of a craze right now and it seems there are a lot of pretenders out there capitalizing on the name. True "Japanese Wagyu A5" - which I can't come close to afford by the way - not only is a breed, but it's fed a very special diet and the beasts are even regularly hand massaged by humans to produce an exceptionally high fat content and amazing marbleing. I think there are American versions where they raise genetic Wagyu but do nothing else and the marbleing is lost. If you shell out the $$$ for Wagyu make sure it is graded at A5 or you are probably paying for something you can get for much less. My local Costco sells USDA 'prime' tri tip for $10/lb that has more marbleing by far than what your picture shows. Choice is going for $8/lb
Here is what true "Wagyu" should look like, it's unmistakable.
This is hands-down the most popular beef in Brazil. Picanha (pronounced pee-KAHN-yah) is known states-side as Top Sirloin Cap, Fat On... and the fat is what makes all the difference. This cut packs a lot of flavor and offers one of the best price-value proposition. While Picanha is best cooked...
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I usually buy the cheapest USDA 'Choice' I can find (pre-pandemic $3.99/lb was not uncommon on sale, and it always turns out excellent. All that it needs is a Santa Maria style dry rub, on medium indirect heat for about 30 minutes and you will have the best, juiciest, taiste you can get on a BBQ. Honest to God, I'll take fresh from the grill Tri-tip over a NY Steak anytime. Enjoy.