I finally tried the Impossible Burger at Crossroads Kitchen a few months back and fell completely in love. However, my diet recently changed and I follow a vegan ketogenic diet. The burger at Crossroads is delicious (and completely vegan) but they do not allow and changes or substitutions. The burger at Umami, same Impossible patty as Crossroads, is more flexible. Now, the bun at Umami is not vegan so if you like your burger with a bun, definitely stick with Crossroads. I can't eat bread on a ketogenic diet, which works for me because it makes me feel bloated and sends me into a food coma which I don't like, so I prefer the Umami bun-less option. They don't have vegan cheese at Umami either BUT I get my burgers, you get two patties at Umami and only one at Crossroads, on a bed of tomato and avocado which is perfect for my vegan keto diet. Then I get veggies on the side and it a delicious meal! The Impossible Burger isn't at every Umami location but our server said they're so popular they're going to expand to more locations soon. Call ahead to make sure they have it and go give it a try!